Condition guides

Breast cancer is the most common cancer in women worldwide.

Lung cancer is the leading cause of cancer death worldwide, but treatment has changed dramatically in the past decade.

Cervical cancer is largely preventable through HPV vaccination and screening, but about 14,000 people in the US are diagnosed each year.

Head and neck cancers start in the mouth, throat, voice box, sinuses, or salivary glands.

Lymphoma encompasses more than 70 types of blood cancer starting in the lymphatic system.

Coronary artery disease — narrowing of the heart's arteries by cholesterol buildup — remains the leading cause of death worldwide.

Obesity affects more than 40% of U.S.

Colorectal cancer is the third most common cancer in the United States, with about 150,000 new diagnoses each year.

Leukemia is cancer of the blood-forming cells in bone marrow.

Stroke happens when blood flow to part of the brain stops, either from a clot or a burst vessel.

Acute coronary syndromes include heart attacks and unstable angina — conditions where blood flow to the heart suddenly drops.

Depression affects more than 20 million adults in the United States each year.

Hodgkin lymphoma is a cancer of the lymphatic system, affecting about 8,000 people each year in the United States.

Prostate cancer is the most common cancer in men, but behavior varies widely — some tumors grow slowly and need minimal treatment, while others are aggressive and require immediate action.

Non-Hodgkin lymphoma includes more than 70 different cancers of the lymphatic system.

Chronic pain affects roughly one in five adults in the U.S., lasting months or years beyond normal healing time.

Anxiety disorders affect about 1 in 5 adults and include generalized anxiety, social anxiety, panic disorder, and phobias.

Squamous cell carcinoma is the second most common skin cancer, usually appearing on sun-exposed areas like the face, ears, and hands.

Hypertension affects more than a billion people worldwide and is managed with several classes of blood pressure medications.

Liver cancer is the sixth most common cancer worldwide and often develops in people with cirrhosis from hepatitis B, hepatitis C, or alcohol-related liver disease.

Gastric cancer (stomach cancer) affects about 26,000 people each year in the United States, with most cases diagnosed at advanced stages.

Heart failure affects about 6 million Americans and occurs when the heart can't pump enough blood to meet the body's needs.

Osteoarthritis affects more than 30 million Americans, causing joint pain and stiffness as cartilage wears down over time.

Pancreatic cancer is often found late, when the tumor has already spread beyond the pancreas.

Type 2 diabetes affects roughly 37 million Americans and happens when the body can't use insulin properly.

Hepatocellular carcinoma is the most common type of primary liver cancer, usually developing in people with chronic liver disease or cirrhosis from hepatitis B, hepatitis C, or fatty liver disease.

Substance use disorder affects millions of people in the United States, involving alcohol, opioids, stimulants, and other drugs.

Ovarian cancer is usually found late, after it has spread beyond the ovaries.

Chronic kidney disease affects about 37 million Americans, often caused by diabetes or high blood pressure.

Acute myeloid leukemia is a fast-moving blood cancer where bone marrow makes abnormal white blood cells.

Gliomas are brain tumors that arise from glial cells, the support tissue of the brain.

Anemia means you don't have enough healthy red blood cells to carry oxygen through your body.

Atrial fibrillation is the most common heart rhythm disorder, affecting millions of people worldwide.

Esophageal cancer is diagnosed in about 21,000 Americans each year, often at advanced stages because early symptoms are subtle.

HIV treatment has transformed the infection from a death sentence into a manageable chronic condition.

Multiple myeloma is a blood cancer of plasma cells in the bone marrow, diagnosed in about 35,000 Americans each year.

Sarcomas are rare cancers arising in bone or soft tissue — muscle, fat, blood vessels, nerves.

Soft tissue sarcoma is a cancer that starts in muscles, fat, blood vessels, nerves, or other connective tissues.

Knee osteoarthritis affects more than 14 million Americans, causing pain, stiffness, and loss of cartilage in the knee joint.

Insomnia affects about one in three adults at some point, and roughly 10% experience chronic insomnia that lasts months or years.

Acute lymphoblastic leukemia (ALL) is a fast-growing blood cancer most common in children, though adults can get it too.

COVID-19 is caused by the SARS-CoV-2 virus and remains a global health concern, though widespread vaccination and prior infection have reduced severe outcomes for many people.

Melanoma is the most serious form of skin cancer, arising from pigment-producing cells.

Alzheimer's disease is the most common cause of dementia, affecting about 6 million Americans.

Type 1 diabetes is an autoimmune disease where the immune system destroys insulin-producing beta cells in the pancreas.

Kidney cancer treatment has advanced significantly, especially for metastatic disease.

Heart attack — myocardial infarction — happens when a coronary artery is suddenly blocked, killing heart muscle.

Renal cell carcinoma is the most common kidney cancer in adults, accounting for about 90% of kidney cancers.

Parkinson's disease affects about one million people in the United States, causing tremor, stiffness, and slow movement as dopamine-producing brain cells die.

Multiple sclerosis is a disease where the immune system attacks the protective coating around nerve fibers in the brain and spinal cord.

Liver cirrhosis — scarring that replaces healthy liver tissue — affects roughly 4 million Americans and is the 12th leading cause of death in the U.S.

Autism spectrum disorder affects roughly 1 in 36 children in the United States.

Traumatic brain injury (TBI) ranges from concussions that resolve in weeks to severe injuries causing long-term disability.

Myelodysplastic syndromes are a group of bone marrow disorders where blood cells don't develop properly, causing low blood counts and a risk of progression to acute myeloid leukemia.

Cerebral palsy is a group of movement disorders caused by early brain injury, affecting about 1 in 345 children in the U.S.

Spinal cord injury affects about 17,000 Americans each year, causing partial or complete loss of movement and sensation below the injury site.

Bladder cancer affects about 80,000 Americans each year, with most cases caught early when the tumor sits on the bladder's inner lining.

Endometrial cancer is the most common gynecologic cancer in the United States, with about 67,000 new cases each year.

Cardiomyopathy is a disease of the heart muscle that makes it harder for the heart to pump blood.

Chronic obstructive pulmonary disease (COPD) affects about 16 million diagnosed Americans and causes progressive airflow limitation that makes breathing harder over time.

Diffuse large B-cell lymphoma is the most common type of non-Hodgkin lymphoma in adults, accounting for about one-third of cases.

Asthma affects more than 25 million Americans and ranges from mild symptoms controlled with occasional inhaler use to severe disease requiring daily medications and frequent hospital visits.

Obstructive sleep apnea affects roughly 30 million Americans, causing breathing to stop repeatedly during sleep when throat muscles relax and block the airway.

Aortic stenosis is a narrowing of the aortic valve that makes the heart work harder to pump blood.

Glioblastoma is an aggressive brain tumor that currently has no cure.

Chronic lymphocytic leukemia is a slow-growing blood cancer where the bone marrow makes too many abnormal lymphocytes.

Post-traumatic stress disorder affects about 6% of Americans at some point in their lives.

Follicular lymphoma is a slow-growing blood cancer that starts in white blood cells called B cells.

Schizophrenia is a chronic mental illness affecting about 1% of people worldwide, causing hallucinations, delusions, disorganized thinking, and social withdrawal.

Epilepsy affects about 1 in 26 people at some point in their lives.

Rheumatoid arthritis affects about 1 in 100 adults, causing the immune system to attack joint linings and sometimes organs.

Alcohol use disorder affects about 14 million adults in the U.S.

Opioid use disorder affects over 2 million Americans and is treated with medications like methadone, buprenorphine, and naltrexone alongside counseling.

Non-alcoholic steatohepatitis (NASH) is liver inflammation and damage caused by fat buildup, not alcohol.

Age-related macular degeneration affects about 20 million Americans, damaging the retina's central area and blurring or erasing straight-ahead vision.

Pulmonary hypertension is high blood pressure in the arteries that carry blood from the heart to the lungs.

Pulmonary arterial hypertension is a rare disease where the small arteries in the lungs narrow and stiffen, forcing the heart to work harder to pump blood through them.

Crohn's disease causes inflammation anywhere in the digestive tract, most commonly in the small intestine and colon.

Peripheral artery disease narrows the arteries that carry blood to the legs and arms, usually from plaque buildup.

More than 48 million Americans have some degree of hearing loss, ranging from mild high-frequency loss to profound deafness.

Lupus is an autoimmune disease where the immune system attacks the body's own tissues, affecting skin, joints, kidneys, brain, and other organs.

Non-alcoholic fatty liver disease affects nearly one in three adults in the US, making it the most common chronic liver condition.

Pulmonary fibrosis is scarring of the lung tissue that makes breathing progressively harder.

Chronic low back pain affects millions of people and can stem from many causes — disc problems, arthritis, nerve compression, muscle strain, or no clear structural issue at all.

Ulcerative colitis causes ongoing inflammation and ulcers in the colon and rectum, affecting about 1 in 200 Americans.

Eczema affects up to 10% of adults and 25% of children in the U.S., causing itchy, inflamed skin that can disrupt sleep and daily life.

Lipoprotein(a), or Lp(a), is a genetic form of cholesterol that raises heart attack and stroke risk independent of LDL.

Cholangiocarcinoma is a rare cancer that starts in the bile ducts, the tubes carrying digestive fluid from the liver.

Urinary incontinence affects roughly one in three women and one in ten men at some point in life, ranging from occasional leaks to complete loss of bladder control.

Graft versus host disease happens when donor immune cells from a stem cell or bone marrow transplant attack the recipient's tissues.

Diabetic neuropathy develops when prolonged high blood sugar damages nerves, most often in the feet and legs.

Glaucoma is a group of eye diseases that damage the optic nerve, usually from high pressure inside the eye.

Most thyroid cancers are highly curable with surgery and radioactive iodine when needed.

Menopause marks the end of menstrual periods, typically occurring in a woman's late 40s or early 50s.

Bone marrow transplantation replaces damaged or diseased marrow with healthy stem cells, either from the patient (autologous) or a donor (allogeneic).

Psoriasis affects about 8 million Americans, causing thick, scaly patches of skin that can itch and crack.

An aortic aneurysm is a bulge in the wall of the aorta, the body's main artery.

Thrombocytopenia means low platelet counts, which can cause easy bruising, bleeding gums, or internal bleeding.

Dry eye disease affects more than 16 million Americans diagnosed and many more undiagnosed.

Amyotrophic lateral sclerosis destroys the nerve cells that control voluntary movement, leading to progressive weakness, loss of speech and swallowing, and eventually respiratory failure.

Amyloidosis happens when misfolded proteins build up in organs, damaging the heart, kidneys, liver, or nerves.

Glomerulonephritis is inflammation of the kidney's filtering units, often triggered by immune system attacks on the glomeruli.

Chronic myeloid leukemia is a blood cancer driven by a genetic abnormality called the Philadelphia chromosome.

Atopic dermatitis affects about 10% of adults and 25% of children, causing itchy, inflamed skin that can disrupt sleep and daily life.

Cataracts are clouding of the eye's natural lens, affecting more than half of Americans over 80.

Systemic sclerosis causes the immune system to attack blood vessels and connective tissue, leading to skin thickening and damage to internal organs — especially the lungs, heart, and digestive tract.

Osteoporosis weakens bones, making them more likely to break from minor falls or everyday activity.

Bipolar disorder affects about 2.8% of U.S.

Fibromyalgia causes widespread pain, fatigue, and sleep problems that often don't respond well to standard pain medications.

Scleroderma causes the immune system to attack connective tissue, leading to skin thickening and potential damage to internal organs including lungs, heart, kidneys, and digestive tract.

ALS (amyotrophic lateral sclerosis) is a disease where nerve cells controlling voluntary movement gradually die.

ADHD is one of the most common neurodevelopmental conditions, affecting around 8% of children and 4% of adults in the U.S.

Influenza kills hundreds of thousands of people globally each year, despite widespread vaccine availability.

Sickle cell disease is an inherited blood disorder affecting about 100,000 Americans, primarily of African descent.

Long COVID describes symptoms that persist for weeks or months after a SARS-CoV-2 infection.

Migraine affects about 1 in 7 people worldwide, causing attacks of severe headache along with nausea, light sensitivity, and sometimes visual disturbances or other neurological symptoms.

Gestational diabetes develops during pregnancy when the body can't make enough insulin to meet increased needs.

Mantle cell lymphoma is a rare B-cell cancer that accounts for about 6% of non-Hodgkin lymphomas.

Pre-eclampsia is high blood pressure that develops during pregnancy, affecting about 5-8% of pregnancies worldwide.

Osteosarcoma is the most common bone cancer in children and young adults, typically appearing in the long bones near the knee or shoulder.

Pancreatitis is inflammation of the pancreas that can be acute (sudden) or chronic (long-lasting).

Vasculitis describes a group of rare diseases where the immune system attacks blood vessels, causing inflammation that can damage organs.

Hepatitis B affects about 300 million people worldwide, with treatments that suppress the virus but rarely eliminate it.

Muscular dystrophy describes a group of genetic diseases that cause progressive muscle weakness and loss.

Gastroesophageal reflux disease affects roughly 20% of adults in the U.S., causing heartburn and damage when stomach acid flows back into the esophagus.

Tuberculosis is a bacterial infection caused by Mycobacterium tuberculosis that primarily affects the lungs but can spread to other organs.

Cystic fibrosis is a genetic disease affecting about 40,000 people in the U.S., caused by mutations in the CFTR gene that makes mucus thick and sticky.

Concussion is a mild traumatic brain injury caused by a blow or jolt to the head.

Irritable bowel syndrome affects about 10-15% of adults worldwide, causing recurring abdominal pain, bloating, and changes in bowel habits.

Neuroblastoma is a childhood cancer that develops from immature nerve cells, most often appearing in the adrenal glands or along the spine.

Pulmonary embolism (PE) is a blood clot in the lungs, usually traveling from leg veins.

Hemophilia A is a bleeding disorder caused by low or missing Factor VIII, a clotting protein.

Endometriosis affects about 10% of women of reproductive age, causing tissue similar to the uterine lining to grow outside the uterus.

Alopecia areata is an autoimmune condition where the immune system attacks hair follicles, causing hair loss in patches on the scalp or body.

Myositis describes inflammatory muscle diseases that cause weakness, pain, and fatigue.

Diabetic retinopathy is the leading cause of vision loss in working-age adults.

Obsessive-compulsive disorder affects about 1 in 40 adults, causing intrusive thoughts and repetitive behaviors that interfere with daily life.

Psoriatic arthritis affects roughly one in three people with psoriasis, causing joint pain, swelling, and sometimes permanent damage if untreated.

Postpartum depression affects about one in seven women after childbirth, with symptoms ranging from persistent sadness and anxiety to difficulty bonding with the baby.

Benign prostatic hyperplasia is non-cancerous enlargement of the prostate gland that affects most men as they age.

Myasthenia gravis is an autoimmune disorder where the body attacks the connections between nerves and muscles, causing weakness that worsens with activity.

Anorexia nervosa is an eating disorder marked by severe food restriction, intense fear of weight gain, and distorted body image.

Polycystic ovary syndrome affects roughly one in ten women of reproductive age.

Anal cancer is rare, accounting for about 2% of digestive tract cancers.

Mesothelioma is a rare cancer of the lining surrounding the lungs, heart, or abdomen, caused by asbestos exposure decades earlier.

Human papillomavirus is the most common sexually transmitted infection, with most sexually active people contracting it at some point.

Idiopathic pulmonary fibrosis is a progressive scarring disease of the lungs that affects about 100,000 people in the United States.

Spinal muscular atrophy is a genetic disease that weakens muscles throughout the body.

Acne affects most people at some point, ranging from occasional breakouts to severe cystic disease that can scar.

Hypertrophic cardiomyopathy is a genetic heart disease where the heart muscle becomes abnormally thick, making it harder for the heart to pump blood.

Iron deficiency anemia affects more than a billion people worldwide and is the most common nutritional deficiency.

Malaria kills over 600,000 people each year, mostly young children in sub-Saharan Africa.

Aplastic anemia is a rare bone marrow failure disorder where the body stops making enough blood cells.

Duchenne muscular dystrophy is a genetic disease that causes progressive muscle weakness, typically diagnosed in early childhood.

Becker muscular dystrophy is a genetic condition caused by mutations in the dystrophin gene, leading to progressive muscle weakness that typically begins in the legs and hips.

Lupus nephritis is kidney inflammation caused by lupus, affecting roughly half of people with systemic lupus erythematosus.

Down syndrome is a genetic condition caused by an extra copy of chromosome 21.

Hepatitis C is a viral infection of the liver that affects about 2.4 million people in the United States.

Retinitis pigmentosa describes a group of inherited eye diseases that damage the light-sensing cells in the retina.

Carpal tunnel syndrome happens when the median nerve gets compressed as it passes through a narrow tunnel in the wrist.

Erectile dysfunction affects about 30 million men in the United States.

Bronchiectasis is permanent widening of the airways in the lungs, usually from repeated infections or inflammation.

Hyperthyroidism means the thyroid gland produces too much hormone, speeding up metabolism.

IgA nephropathy is the most common kidney inflammation worldwide, caused by deposits of IgA antibodies in the kidney's filtering units.

Beta thalassemia is an inherited blood disorder that reduces hemoglobin production, causing anemia that ranges from mild to life-threatening.

Vulvar cancer accounts for about 6% of gynecologic cancers in the United States, with roughly 6,000 new cases diagnosed each year.

Hidradenitis suppurativa causes painful lumps, abscesses, and tunneling wounds in areas where skin rubs together — armpits, groin, under breasts, buttocks.

Graves' disease is an autoimmune condition where the thyroid gland produces too much hormone, causing rapid heartbeat, weight loss, anxiety, and sometimes bulging eyes.

Ewing sarcoma is a rare bone and soft tissue cancer that most often affects children and young adults.

Celiac disease is an autoimmune condition where eating gluten triggers the immune system to damage the small intestine.

Neurofibromatosis includes several genetic conditions that cause tumors to grow along nerves.

Deep vein thrombosis is a blood clot in a deep vein, usually in the leg.

Primary biliary cholangitis is a chronic liver disease where the immune system attacks bile ducts, causing bile to back up and damage liver tissue.

Testicular cancer is the most common cancer in men ages 15 to 35, with about 9,000 new cases in the U.S.

Meningiomas are tumors that grow from the membranes covering the brain and spinal cord.

Dystonia causes involuntary muscle contractions that twist the body into repetitive movements or abnormal postures.

Charcot-Marie-Tooth disease is a group of inherited nerve disorders affecting about 1 in 2,500 people.

Ankylosing spondylitis is a form of inflammatory arthritis that primarily affects the spine and sacroiliac joints, causing pain and stiffness that often starts in early adulthood.

Uterine fibroids are noncancerous growths in the uterus that affect most women at some point, though not all cause symptoms.

Essential tremor causes rhythmic shaking, usually in the hands, that happens during movement or when holding a position.

Uveitis is inflammation inside the eye that can blur vision, cause pain, and lead to permanent damage if untreated.

Dilated cardiomyopathy means the heart's main pumping chamber enlarges and weakens, reducing its ability to pump blood.

Binge eating disorder is the most common eating disorder in the United States, affecting about 2% of adults.

Vitiligo causes patches of skin to lose pigment, affecting about 1% of people worldwide.

Gastroparesis means the stomach empties too slowly, causing nausea, vomiting, bloating, and unpredictable blood sugar in people with diabetes.

Tinnitus — ringing, buzzing, or hissing in the ears — affects about 15% of adults.

Bulimia nervosa is an eating disorder marked by cycles of binge eating followed by purging through vomiting, laxatives, or excessive exercise.

Huntington's disease is a fatal inherited brain disorder caused by a single gene mutation.

Dermatomyositis causes muscle weakness and a distinctive skin rash, often appearing on the face, knuckles, and chest.

Sarcoidosis causes clumps of immune cells to form in organs, most often the lungs and lymph nodes, though it can affect the heart, skin, eyes, and nervous system.

Borderline personality disorder affects about 1.4% of adults in the U.S.

Hydrocephalus happens when cerebrospinal fluid builds up in the brain's ventricles, often requiring a shunt to drain excess fluid.

Polycystic kidney disease causes fluid-filled cysts to grow in the kidneys, gradually replacing healthy tissue.

Fabry disease is a rare genetic condition where the body can't break down a specific fat, causing it to build up in cells throughout the body.

Wet age-related macular degeneration occurs when abnormal blood vessels grow under the retina and leak fluid, causing rapid vision loss in the center of the visual field.

Giant cell arteritis is an inflammation of blood vessels, especially those supplying the head and eyes.

Polymyalgia rheumatica causes muscle pain and stiffness in the shoulders, hips, and neck, typically in people over 50.

Hemophilia B is a genetic bleeding disorder caused by missing or low levels of clotting factor IX.

Eosinophilic esophagitis is a chronic immune condition where a type of white blood cell builds up in the esophagus, causing trouble swallowing and food getting stuck.

Cleft palate is a gap in the roof of the mouth present at birth, affecting about 1 in 1,600 babies in the U.S.

Hypothyroidism means the thyroid gland doesn't make enough thyroid hormone, slowing metabolism and causing fatigue, weight gain, and cold sensitivity.

Wilms tumor is a kidney cancer that occurs almost exclusively in children, typically before age 5.

Acute kidney injury happens when the kidneys suddenly stop filtering waste from the blood, often during severe illness, surgery, or after certain medications.

Mild cognitive impairment (MCI) describes memory or thinking changes that are noticeable but don't interfere much with daily life.

Fallopian tube cancer is rare, accounting for about 1% of gynecologic cancers.

Sepsis is a life-threatening condition where the body's response to infection causes widespread inflammation and organ damage.

Major depressive disorder affects roughly 8% of U.S.

Hypercholesterolemia means having high cholesterol in the blood, increasing the risk of heart attack and stroke.

Diabetes affects how the body uses glucose, a sugar the body needs for energy.

Periodontitis is gum disease that destroys the bone supporting your teeth.

Atherosclerosis is the buildup of fatty plaque inside arteries, narrowing them and restricting blood flow.

Myopia, or nearsightedness, affects about one-third of adults in the United States and is rising worldwide, particularly in children.

Cardiovascular disease remains the leading cause of death worldwide, but death rates have dropped sharply over the past 30 years thanks to statins, blood pressure medications, and improved heart attack care.

Ischemic stroke happens when a blood clot blocks flow to part of the brain, killing brain cells within minutes.

Acute coronary syndrome includes heart attacks and unstable angina — sudden blockages in the heart's arteries.

Knee osteoarthritis affects more than 14 million Americans, making it the most common joint disease.

Non-small cell lung cancer accounts for about 85% of lung cancers.

Metabolic syndrome is a cluster of conditions — high blood pressure, high blood sugar, excess abdominal fat, and abnormal cholesterol — that together raise the risk of heart disease, stroke, and type 2 diabetes.

Rectal cancer is cancer in the last several inches of the large intestine.

Sarcopenia is the progressive loss of muscle mass and strength that happens with aging.

Spinal cord injury affects about 17,000 Americans each year, most often from car crashes, falls, or sports injuries.

Low back pain affects most adults at some point, and for about 20% it becomes chronic.

Infertility affects about one in eight couples trying to conceive.

Heart disease covers a range of conditions affecting the heart and blood vessels, including coronary artery disease, heart failure, arrhythmias, and valve problems.

Dementia describes a group of symptoms affecting memory, thinking, and daily function, with Alzheimer's disease accounting for about 60-70% of cases.

Cataracts are clouding of the eye's natural lens, affecting more than half of Americans by age 80.

Cardiovascular disease — including heart attacks, heart failure, and stroke — remains the leading cause of death worldwide.

Anxiety disorders affect about 30% of adults at some point in their lives.