Hypertriglyceridaemia is a condition where you have too much of a type of fat called triglycerides in your blood. This condition affects about 1 in 5 adults and can raise your risk of heart disease and, at very high levels, inflammation of the pancreas.

Hypertrophic cardiomyopathy is a heart condition where the muscle becomes abnormally thick, making it harder for the heart to pump blood properly. While many people live without symptoms, this genetic disease can lead to serious complications, including sudden cardiac death, particularly in young people and athletes.

A hypertrophic scar is a thick, raised scar that develops when your body produces too much collagen during the healing process. Unlike normal scars that fade and flatten over time, these scars remain elevated and can cause itching, pain, and movement restrictions, though they typically stay within the boundaries of the original wound.

Hypervolaemia occurs when your body holds onto too much fluid. This excess can cause swelling, breathing difficulties, and potentially serious heart problems. Understanding the causes and knowing how to manage this condition can help protect your health.

Hypoaesthesia is a decreased sensitivity to touch that can make you feel strangely numb or insensitive in parts of your body. While often temporary and harmless, this reduced sensation can sometimes indicate a more serious underlying condition that requires medical attention.

Hypoalbuminaemia is a widespread condition where the level of albumin protein in your blood falls below normal levels. This protein plays essential roles in keeping fluid inside blood vessels and moving important substances throughout your body. The condition is especially common among people who are hospitalized or seriously ill, and it often signals an underlying health problem that needs attention.

Hypocalcaemia is a treatable condition that occurs when calcium levels in the blood fall below normal. While some people experience no symptoms at all, others may face serious complications affecting the nervous system and heart if left untreated.

Hypochondroplasia is a genetic condition that affects how bones grow, leading to short stature and shortened limbs. While it shares similarities with achondroplasia, its features are often milder and may not be noticed until early childhood.

Hypochromic anaemia is a blood condition where red blood cells appear paler than normal due to lower levels of haemoglobin, the protein that carries oxygen throughout the body. This condition most commonly occurs because of iron deficiency, though other causes exist, and affects millions of people worldwide, particularly women and young children.

Hypoglycaemia is a condition where blood sugar drops below safe levels, causing symptoms that range from shakiness and sweating to confusion and, in severe cases, loss of consciousness. While most common in people with diabetes who take insulin or certain medications, understanding how to recognize and treat low blood sugar quickly can prevent serious complications.

Male hypogonadism is a condition where the body doesn’t produce enough testosterone, the hormone essential for male development and characteristics, or enough sperm, or both. This condition can develop before birth, during puberty, or in adulthood, affecting physical development, sexual function, and overall health.

Hypomagnesemia is a condition where your blood contains less magnesium than normal. This essential mineral plays a vital role in keeping your heart, brain, and muscles working properly, and low levels can lead to symptoms ranging from muscle cramps to dangerous heart rhythm problems.

Hyponatraemia occurs when the level of sodium in your blood drops too low, creating an imbalance between water and sodium in your body. This common condition can range from mild with few symptoms to severe and life-threatening, affecting your brain and other vital organs.

Hypoparathyroidism is a rare condition where the body doesn’t make enough parathyroid hormone, leading to low calcium levels in the blood. While most cases occur after neck surgery, this treatable condition can be managed with proper care and supplements.

Hypophosphatasia is a rare genetic condition that causes bones and teeth to become soft and weak, affecting people in very different ways depending on when symptoms first appear and how severe they are.

Hypopituitarism is a rare condition where your pituitary gland doesn’t produce enough of the hormones your body needs to function properly. This can affect growth, metabolism, reproduction, and many other vital processes, requiring careful diagnosis and often lifelong treatment.

Hypoplastic left heart syndrome is a serious heart condition that babies are born with, where the left side of the heart doesn’t develop properly and is too small to pump blood effectively to the body.

Low blood pressure, also known as hypotension, occurs when blood flows through your blood vessels at lower than normal pressures. While many people have naturally low blood pressure without problems, sometimes it can signal an underlying health issue or cause troubling symptoms like dizziness and fainting.

Hypothyroidism, also called underactive thyroid, occurs when your thyroid gland doesn’t produce enough thyroid hormones to meet your body’s needs. This common condition affects nearly 5 out of 100 Americans and can slow down many of your body’s functions, causing fatigue, weight gain, and other symptoms that develop gradually over time.

Hypotonia is a condition where muscles have less tension than normal, often making infants appear “floppy” or limp when held. While the condition itself is easily recognized, finding out what causes it can be challenging, and early diagnosis and treatment play an important role in helping children develop their movement skills.

Hypotransferrinaemia is an extremely rare genetic blood disorder that causes a puzzling combination: severe anemia despite iron overload in the body. This life-threatening condition requires lifelong treatment with regular plasma infusions to survive.

Hypoxia is a serious medical condition where your body’s tissues don’t receive enough oxygen. When oxygen levels drop too low, you might feel confused, restless, or struggle to breathe, and your skin may turn bluish. This condition can become life-threatening within minutes if not treated promptly.

Hypoxic-ischaemic encephalopathy is a serious brain injury that occurs when a newborn’s brain doesn’t receive enough oxygen and blood during birth or shortly after. While some children recover completely, others may face lifelong challenges affecting their movement, learning, and development.

A hysterectomy is a surgical procedure to remove the uterus. After this surgery, you can no longer become pregnant and will not have menstrual periods. It is one of the most common surgeries for women, with approximately 600,000 performed each year in the United States.

Ichthyosis is a group of rare skin conditions that cause dry, scaly skin resembling fish scales. Most types are inherited and present from birth, though the condition can occasionally develop later in life.

Idiopathic generalised epilepsy is a brain disorder that causes repeated seizures without any identifiable structural brain damage or injury. It affects about one third of all people with epilepsy and is believed to have a strong genetic basis, typically beginning in childhood or adolescence.

Idiopathic inflammatory myopathy is a group of rare autoimmune diseases that cause chronic muscle inflammation and weakness, often affecting daily activities like climbing stairs or lifting objects, while also potentially impacting other organs including the skin, lungs, and heart.

Idiopathic intracranial hypertension is a rare condition where pressure builds up around the brain without a known cause. While it’s not life-threatening, it can lead to permanent vision loss if left untreated, making early diagnosis and treatment essential.

Idiopathic pulmonary fibrosis is a serious lung disease where tissue surrounding the air sacs becomes thick, stiff, and scarred for reasons that remain unknown. This progressive condition makes breathing increasingly difficult over time, affecting mostly people in their 60s and 70s.

IgA nephropathy is a kidney disease where a specific protein builds up in the kidneys, causing inflammation and damage over time. While it often progresses slowly and may go unnoticed for years, it is one of the most common kidney diseases worldwide and can eventually lead to kidney failure if not properly managed.

Your immune system is your body’s defense network, but when it malfunctions, it can attack your own healthy cells, fail to protect you from germs, or overreact to harmless substances. These immune system disorders affect millions of people and can range from mild to life-threatening conditions.

Immune thrombocytopenia (ITP) is a rare blood disorder where the body’s own immune system mistakenly attacks and destroys platelets, the tiny cells that help blood clot. This can lead to unusual bruising, small red spots on the skin, and bleeding that’s harder to stop than normal.

Immune-mediated enterocolitis is a serious inflammatory condition affecting the intestines that can develop in people taking immune checkpoint inhibitors for cancer treatment, occurring in up to 44% of patients treated with combination therapies and requiring prompt recognition and treatment to prevent life-threatening complications.

Immune-mediated myositis is a group of rare autoimmune muscle diseases where the body’s defense system mistakenly attacks its own muscle tissue, causing inflammation, weakness, and pain that can significantly affect daily life.

Immune-mediated renal disorders are a group of kidney diseases where the body’s own defense system mistakenly attacks the kidneys, causing inflammation and damage that can lead to serious complications if left untreated.

Immunodeficiency is a condition where your body’s defense system cannot fight infections as it should. When you have immunodeficiency, you get sick more often and your infections may be more serious, last longer, or be harder to treat than in people with a healthy immune system.

Congenital immunodeficiency disorders are a group of inherited conditions where the immune system doesn’t work properly from birth, making it harder for the body to fight off infections and other health challenges.

Immunoglobulin G4-related disease is a rare immune disorder that can affect almost any organ in the body, often appearing as tumor-like masses that may be mistaken for cancer. Understanding this complex condition is essential for proper diagnosis and treatment.

Immunosuppression is a condition where your body’s natural defense system doesn’t work as well as it should, making it harder to fight off infections and diseases. This can happen because of certain illnesses, medications, or medical treatments like organ transplants.

Impaired gastric emptying, also known as gastroparesis, is a condition where the stomach takes much longer than normal to move food into the small intestine, even though there is no physical blockage preventing this movement.

Implantation is a crucial early stage of pregnancy when a fertilized egg attaches to the uterine wall, but complications during this process can lead to various outcomes ranging from normal pregnancy symptoms to serious fertility challenges.

Inborn errors of metabolism are a group of rare genetic conditions that prevent the body from properly converting food into energy and removing waste products. While each individual disorder is uncommon, together they affect approximately 1 in every 1,500 to 2,500 births worldwide, making early recognition and proper management essential for improving outcomes.

An incisional hernia develops when tissue or organs push through weakened abdominal muscles at the site of a previous surgery, creating a bulge near your surgical scar that may appear months or even years after the procedure.

Inclusion body myositis is a slowly progressive muscle disease that most commonly affects people over 45, causing gradual weakness in the limbs and fingers. While there is currently no cure, understanding this condition and staying active can help maintain quality of life.

Urinary incontinence—the involuntary leakage of urine—is a common condition affecting millions of people, but it doesn’t have to disrupt your life. While it becomes more prevalent with age, it’s not an inevitable part of aging, and treatments are available to help you regain control.

Indolent systemic mastocytosis is the most common form of a rare chronic disorder where abnormal mast cells build up in the body, mainly in the bone marrow and skin, causing symptoms that can range from mild to severely debilitating.

Infant sedation involves giving medicine to babies and young children to help them stay calm, relaxed, or asleep during medical tests and procedures, ensuring safety and comfort while allowing healthcare providers to complete necessary examinations.

Infantile apnoea is a breathing condition where babies stop breathing for periods of time during sleep or rest, often accompanied by changes in heart rate, skin color, or muscle tone.

Infantile spasms are a rare but serious type of seizure that affects babies, typically between 3 and 12 months of age. These brief seizures can have significant effects on a young child’s developing brain, making early recognition and treatment critically important.

An infection happens when harmful germs enter your body, multiply, and cause your body to react. These tiny organisms—bacteria, viruses, fungi, or parasites—can trigger symptoms ranging from mild discomfort to life-threatening illness.

When the immune system doesn’t work as it should, even common germs can become serious threats. Understanding how to protect yourself when your body’s defenses are weakened is essential for staying healthy and safe.

Infectious pleural effusion continuously threatens health worldwide, and despite medical advances, the condition can lead to serious complications with fatality rates reaching up to 20%, rising even higher in elderly patients with underlying conditions.

Infective uveitis is inflammation of the middle layer of the eye caused by germs like viruses, bacteria, fungi, or parasites. It accounts for 15 to 20 percent of uveitis cases in the United States and requires early treatment to prevent vision loss.

Infertility affects millions of people worldwide, preventing pregnancy despite regular, unprotected sex. While it can be a frustrating and unexpected challenge for couples hoping to become parents, many safe and effective treatments are available that can boost the chances of having a baby.

Female infertility affects millions of women worldwide, making it difficult or impossible to achieve pregnancy even after consistent attempts. Understanding the causes, recognizing the signs, and knowing the available treatments can help women and couples navigate this challenging journey.

Male infertility affects approximately one in seven couples trying to conceive, with the male partner being solely or partially responsible in about half of all infertility cases. While the inability to have a biological child can be emotionally challenging, many treatment options and assisted reproductive technologies are available to help couples achieve pregnancy.

Inflammation is your body’s natural defense system, responding to injuries and invaders like germs to promote healing. While this process is essential for protection, chronic inflammation that persists without reason can harm healthy tissues and contribute to many serious diseases.

Inflammatory bowel disease is a lifelong condition that causes swelling and inflammation in the digestive tract, but with the right treatment and care, most people can lead active lives with long periods free from symptoms.

Inflammatory breast cancer at stage IV is a rare and highly aggressive form of breast cancer that has spread beyond the breast to other parts of the body. Understanding this condition, its symptoms, and treatment options is essential for patients and their families navigating this challenging diagnosis.

Inflammatory breast cancer is a rare and aggressive form of breast cancer that causes the breast to look red, swollen, and inflamed, often without a lump that can be felt.