Oesophagectomy is major surgery to remove all or part of the oesophagus, the tube that carries food from your throat to your stomach. This procedure is most often performed to treat oesophageal cancer and requires careful preparation, extensive surgery, and a long recovery period.

Oesophagogastroscopy, also called upper endoscopy or EGD, is a medical procedure that allows doctors to examine the inside of your upper digestive system using a flexible tube with a camera. This procedure helps diagnose and sometimes treat various digestive problems affecting your esophagus, stomach, and the beginning of your small intestine.

Oestrogen receptor gene overexpression occurs when cells produce too much of the protein that responds to oestrogen hormones, affecting how genes are turned on and off in the body, with important implications for breast cancer development and treatment.

Onychomycosis is a fungal infection of the nail that can make your nails thick, discolored, and brittle. While it’s not usually painful, this common condition affects millions of people and can significantly impact daily life and self-confidence.

Open-angle glaucoma is a silent eye condition that can steal your vision without warning. Understanding this disease and getting early treatment can help protect your sight for years to come.

Ophthalmoplegia is a condition that affects the muscles controlling your eye movements, causing weakness or paralysis that can lead to drooping eyelids, double vision, and difficulty moving your eyes. Understanding this condition and its various forms is essential for proper diagnosis and treatment.

Optic atrophy is a serious condition affecting the optic nerve, which connects your eyes to your brain. It can lead to permanent vision loss and even blindness, making early detection and treatment of underlying causes critically important.

Optic glioma is a slow-growing brain tumor that develops along the optic nerve, the pathway that carries visual signals from the eye to the brain. While this is a serious condition, it has a high cure rate and primarily affects young children, with most cases diagnosed before the age of 5.

Optic ischaemic neuropathy is a serious condition that causes sudden vision loss when the optic nerve doesn’t receive enough blood flow. It most commonly affects people over 50 and requires urgent medical attention to prevent permanent damage.

Oral herpes is a very common viral infection that affects the mouth and lips, causing small blisters known as cold sores. About half of adults in the United States have this infection, often contracted during childhood through everyday contact like kissing. While there is no cure, the condition can be effectively managed with treatment.

Oral lichen planus is a long-lasting inflammatory condition that affects the tissue lining inside your mouth, appearing as white patches, red areas, or open sores, and while it cannot be cured, treatments can help manage symptoms and reduce discomfort.

Oral neoplasm, also known as mouth cancer or oral cavity cancer, affects the lips, tongue, gums, and other parts of the mouth. Early detection can make a significant difference in treatment success, but many cases are discovered only in later stages.

Organ donation offers a second chance at life to people with life-threatening diseases or injuries to their vital organs. One organ donor can save up to eight lives and enhance the lives of 75 others through organ, eye and tissue donation.

Ornithine transcarbamoylase deficiency is a rare inherited disorder that prevents the body from safely removing ammonia from the blood, potentially causing severe brain damage if ammonia levels become too high.

Oropharyngeal cancer forms in the middle section of your throat and can affect your ability to eat, drink, and speak. While the disease is relatively rare, affecting about 53,000 people in the U.S. each year, its incidence is rising—especially cases linked to human papillomavirus (HPV) infection, which now accounts for 60% to 70% of all oropharyngeal cancers.

Recurrent oropharyngeal cancer means the cancer has returned after initial treatment. Despite advances in treatment and the generally favorable prognosis of oropharyngeal cancer—especially when linked to human papillomavirus (HPV)—some patients will experience recurrence, which requires specialized care and a personalized approach to treatment.

Oropharyngeal squamous cell carcinoma is a type of cancer that develops in the middle part of the throat, affecting areas like the tonsils, base of the tongue, and soft palate. While cases are rising, especially in younger people, treatment options are improving and cure rates are increasing, particularly for cancers linked to human papillomavirus (HPV).

Orthostatic hypotension is a sudden drop in blood pressure that happens when you stand up from sitting or lying down. This condition can make you feel dizzy or lightheaded, and sometimes even cause you to faint. While it can affect anyone, it becomes more common with age and can significantly impact daily life.

Osteoarthritis is the most common form of arthritis worldwide, affecting millions of people. While there is no cure, understanding this condition and knowing how to manage it can help you maintain an active, fulfilling life and slow its progression.

Osteochondrodysplasia represents a group of rare hereditary disorders that disrupt the normal development of bone and cartilage, leading to skeletal abnormalities and short stature in affected individuals.

Osteogenesis imperfecta is a genetic disorder that causes bones to break easily, often from little or no force. While some people experience only a few fractures in their lifetime, others may face hundreds of breaks, along with additional health challenges affecting the teeth, hearing, spine, and breathing.

Osteomyelitis is a serious bone infection that can affect anyone, but early diagnosis and treatment are crucial to prevent permanent damage and restore normal function.

Acute osteomyelitis is a serious bone infection that develops rapidly when bacteria or fungi spread to your bones, usually through your bloodstream. If not treated quickly, it can cause permanent bone damage and serious complications.

Osteonecrosis of the jaw is a rare but serious condition where bone tissue in the jaw dies and becomes exposed through the gums. While uncommon, it can occur in people taking certain medications for osteoporosis or cancer, particularly after dental procedures.

Osteopenia is a condition where your bones lose density and become weaker than normal, though not weak enough to be classified as osteoporosis. About 40 million Americans have osteopenia, and it typically develops after age 50, though the exact timing depends on how strong your bones were when you were younger.

Osteoporosis weakens your bones, making them fragile and more likely to break from even a minor fall or bump. Often called a “silent disease,” it develops slowly over many years without obvious symptoms, and many people only discover they have it after breaking a bone.

Postmenopausal osteoporosis is a condition where bones become weak and brittle after menopause, affecting millions of women worldwide. Understanding this condition and taking proactive steps can help protect your bone health and reduce the risk of fractures.

Osteosarcoma is a type of bone cancer that most often affects teenagers and young adults, though it can occur at any age. It typically develops in the long bones of the arms and legs, especially near the knee, and can cause pain, swelling, and limited movement.

Metastatic osteosarcoma is when bone cancer spreads from its original location to other parts of the body, most commonly the lungs. This advanced form of bone cancer presents significant treatment challenges and has a less favorable outlook than cancer that remains in one place.

Recurrent osteosarcoma is cancer that has returned after initial treatment or has not responded to therapy. It occurs in 30-50% of patients who initially had cancer confined to one area, and in 80% of patients who had cancer that had already spread at diagnosis.

Osteotomy is a surgical procedure that cuts and reshapes bones to correct alignment problems, relieve pain, and restore movement to damaged joints throughout the body.

Otitis media is an infection or inflammation of the middle ear, the space behind your eardrum. It’s the most common childhood illness after colds, affecting up to 80% of children before they reach school age. While it can be painful and worrying for parents, most ear infections clear up on their own, though some cases may need antibiotics or other treatments.

Ovarian cancer is a disease where abnormal cells in the ovaries grow out of control. It often develops without obvious symptoms in the early stages, making early detection challenging. Understanding the warning signs, risk factors, and treatment options can help you take charge of your health.

Metastatic ovarian cancer

When ovarian cancer returns after treatment, it brings new challenges—but also new possibilities for care. Understanding what recurrence means and the options available can help you navigate this next phase of your journey.

Stage 3 ovarian cancer has spread beyond the pelvis into the abdominal cavity or to nearby lymph nodes. While this is an advanced form of the disease, treatment combining surgery and chemotherapy can be effective, and many people continue to live full lives after diagnosis.

Stage 4 ovarian cancer is the most advanced form of the disease, where cancer cells have spread beyond the ovaries and abdomen to distant parts of the body such as the liver, lungs, or other organs. While this is a serious diagnosis, treatment options exist to help control the cancer, extend life, and improve quality of life.

Epithelial ovarian cancer is the most common and deadliest form of ovarian cancer, often diagnosed at advanced stages when it has already spread beyond the ovaries. This disease can be difficult to detect early because symptoms are often subtle or mistaken for less serious conditions, making awareness and regular medical checkups essential.

When ovarian cancer spreads beyond the ovaries to distant parts of the body, it becomes metastatic ovarian cancer, classified as Stage IV. This advanced form of the disease represents a significant challenge, yet understanding treatment options and available therapies provides hope for patients and their families.

When ovarian epithelial cancer returns after treatment, it presents new challenges but also new treatment options. Understanding recurrence patterns, symptoms, and available therapies can help patients and their families navigate this difficult journey with greater confidence.

Stage 3 ovarian epithelial cancer has spread beyond the pelvis into the abdomen or nearby lymph nodes, but with modern treatment approaches combining surgery and chemotherapy, many patients can achieve long-term survival.

Stage IV ovarian epithelial cancer is the most advanced form of this disease, where cancer has spread beyond the ovaries to distant parts of the body such as the liver or lungs. While this diagnosis is serious, treatment combining surgery and chemotherapy can help control the disease and improve quality of life.

Stage IV ovarian germ cell cancer is the most advanced form of this rare cancer, where the disease has spread from the ovaries to distant organs like the liver or lungs. Though this represents a serious diagnosis, treatment options including surgery and chemotherapy can help manage the disease and improve outcomes.

Ovarian granulosa cell tumours are rare hormone-producing tumours that account for about 5% of all ovarian cancers. Most are diagnosed early and grow slowly, often causing symptoms related to high estrogen levels such as irregular bleeding or early puberty in young girls.

Ovarian low malignant potential tumours are abnormal growths that develop in the ovaries. Unlike typical cancers, these tumours have unusual cells that may become cancer but usually do not, and they often affect younger women with an excellent chance of recovery.

Overweight affects billions of people worldwide, and understanding this condition is the first step toward making positive changes for your health and well-being.

Oxygen saturation measures how much of the oxygen-carrying protein in your blood is actually loaded with oxygen. It’s a vital indicator of how well your body is getting the oxygen it needs to function properly, and monitoring it has become a standard part of medical care.

Oxygen therapy provides extra oxygen to people whose bodies cannot get enough on their own. This treatment helps prevent serious complications from low oxygen levels and can greatly improve quality of life for those with breathing difficulties.

Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) is a condition where children suddenly develop severe mental and behavioral changes, often seemingly overnight, transforming happy, healthy children into those struggling with obsessive thoughts, restricted eating, and other distressing symptoms.

Paedophilia is a sexual disorder characterized by sexual attraction to prepubescent children. Understanding this condition, how it differs from child sexual abuse, and what treatment options exist is essential for prevention and support.

Paget’s disease of the vulva is a rare skin condition affecting the external female genital area. Although it accounts for only about 1% of vulvar cancers, it requires careful diagnosis and treatment because it often extends beyond visible borders and has a tendency to recur.

Pain is a complex signal from your body that something may be wrong, affecting millions of people worldwide through physical discomfort and emotional challenges that can disrupt daily life.

Pain in the extremities affects the arms, legs, hands, and feet, and can make everyday activities like walking, lifting, or holding objects challenging.

Palmoplantar pustulosis is a long-lasting skin condition that causes painful, fluid-filled blisters on the palms of your hands and soles of your feet. While it shares some features with psoriasis, it is difficult to treat and can seriously affect your ability to use your hands and walk comfortably.

Heart palpitations are a common experience where your heartbeat becomes more noticeable or feels unusual. While they can be alarming, most palpitations are harmless and caused by everyday factors like stress, caffeine, or exercise.

Pancoast’s tumour is a rare type of lung cancer that develops in the top part of the lung and causes unusual symptoms like severe shoulder pain and arm weakness rather than typical lung cancer signs such as coughing or breathing problems.

Pancreatic cancer begins when cells in the pancreas grow out of control, forming a tumor. This disease is difficult to detect early and often spreads before symptoms appear, making it one of the most challenging cancers to treat.

Metastatic pancreatic cancer, also called stage IV pancreatic cancer, is a highly aggressive disease where cancer cells have spread beyond the pancreas to distant organs. Despite a grim outlook, with a five-year survival rate as low as 2%, recent advances in treatment are offering new hope to patients facing this challenging diagnosis.

Recurrent pancreatic cancer means the disease has returned after treatment, presenting significant challenges even for those who successfully underwent surgery and therapy.

Stage IV pancreatic cancer occurs when the disease has spread beyond the pancreas to other parts of the body. While this is a serious diagnosis, understanding treatment options and supportive care can help patients and families navigate this challenging time.