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.

Inflammatory myofibroblastic tumor is a rare neoplasm characterized by the growth of specialized cells interspersed with inflammatory cells, occurring most commonly in children and young adults, particularly in the lungs, abdomen, and retroperitoneum.

Influenza is a contagious respiratory illness caused by viruses that can make you feel very sick, and in some cases, lead to serious complications or even death. The good news is that getting vaccinated every year and taking simple preventive steps can protect you and those around you.

An inguinal hernia happens when tissue from inside your belly pushes through a weak spot in your lower abdominal wall into your groin area, creating a noticeable bulge that may cause discomfort or pain.

Injection site pain is a common reaction that occurs after receiving an injection, affecting where the needle enters the skin. While it can be uncomfortable, understanding what causes this pain and how to manage it can help make injections easier to tolerate.

Millions of people experience injuries every year, ranging from minor cuts and bruises to life-threatening conditions. Understanding what injuries are, how they happen, and how to recover can help you navigate these challenging experiences and get back to your daily life.

A brachial plexus birth injury occurs when the network of nerves connecting the neck to the arm is damaged during delivery, affecting between one and three babies out of every 1,000 births. While most infants recover fully within a few months, some require specialized treatment to regain movement in their shoulder, arm, and hand.

Inner ear disorders can disrupt both hearing and balance, causing symptoms like dizziness, hearing loss, and ringing in the ears. These conditions affect the delicate structures deep within the ear that help us hear sounds and maintain our sense of equilibrium.

Insomnia is a common sleep disorder that affects how you feel and function during the day. About 10% of people worldwide experience insomnia that qualifies as a medical condition, but there are many effective ways to improve your sleep.

Insulin resistance is a condition where your body’s cells don’t respond properly to insulin, a hormone that helps control blood sugar levels. This complex condition affects millions of people and can lead to serious health problems, but many people can take steps to prevent or reverse it through lifestyle changes.

If you have type 2 diabetes and other treatments are no longer keeping your blood sugar within a healthy range, your healthcare provider may prescribe insulin. This doesn’t mean your diabetes has become type 1 or that you’ve failed to manage it properly—it’s simply another treatment option that can help keep you healthy.

Intellectual disability is a lifelong condition that affects how a person learns, thinks, and handles everyday tasks. While it presents unique challenges, most people with intellectual disability can live healthy, productive lives with the right support and services.

Intermittent claudication is muscle pain in your legs that happens when you’re active and goes away when you rest. This pain is a sign that your muscles aren’t getting enough oxygen because of blood flow problems. With proper treatment and lifestyle changes, most people can prevent the condition from getting worse and maintain an active life.

Interstitial lung disease is a term for a group of over 200 conditions that cause inflammation and scarring in the lungs, making it harder to breathe and get enough oxygen into your body.

Intervertebral disc degeneration is a common condition where the cushioning discs in your spine break down over time, potentially causing back or neck pain that can interfere with daily activities. While almost everyone experiences some disc wear as they age, not everyone develops symptoms, and effective management strategies can help you maintain an active, comfortable life.

Intervertebral disc protrusion is a common condition where the disc between the vertebrae in your spine bulges outward, pressing against nearby nerves and causing pain, numbness, or weakness. While it can significantly disrupt daily life, most people find relief through non-surgical treatments within a few weeks or months.

Intestinal infarction is a serious and life-threatening condition that occurs when blood flow to the intestines is severely reduced or completely blocked. Despite being uncommon, it has a very high death rate and requires immediate medical attention to prevent permanent damage or death.

Intestinal ischaemia is a serious medical condition that occurs when blood flow to the intestines becomes reduced or blocked, depriving these organs of the oxygen they need to function properly. Though uncommon, this condition can be life-threatening if not treated quickly.

Intestinal obstruction is a serious medical condition where food, liquid, gas, or stool cannot pass through the small or large intestine normally. This blockage requires immediate medical attention to prevent dangerous complications.

An intracranial aneurysm is a dangerous bulge in a blood vessel in your brain that can burst without warning, causing life-threatening bleeding. While most brain aneurysms are small and may never cause problems, a ruptured aneurysm is a medical emergency that can lead to stroke, brain damage, or death.

Calcium deposits in the brain are surprisingly common and appear in many different forms, ranging from normal age-related changes to signs of serious disease. Understanding these calcifications can help identify their cause and guide appropriate care.

An intraductal papillary mucinous neoplasm (IPMN) is a cyst that grows in the ducts of your pancreas and has the potential to become cancer. While not all of these tumors turn into cancer, researchers believe they are responsible for 20% to 30% of pancreatic cancer cases.

Invasive breast carcinoma is the most common type of breast cancer, affecting thousands of women each year. Understanding this condition, its symptoms, and treatment options can help patients and their families navigate the journey ahead with greater confidence.

Invasive ductal carcinoma is the most common type of breast cancer, accounting for about 80% of all cases. It starts in the milk ducts of the breast and can spread to surrounding tissue and other parts of the body. Early detection through mammography often allows doctors to treat it successfully before it spreads.

Invasive lobular carcinoma is the second most common type of breast cancer, accounting for 10 to 15 percent of all invasive breast cancers. Unlike other breast cancers that form lumps, this type grows differently, making it harder to detect but still treatable with proper diagnosis and care.