Diseases & Symptoms

Pain is an unpleasant sensory and emotional experience, shaped by nerve signaling, brain processing, and psychosocial context; it protects the body but can persist as disease.

Palpitations are a sensation of an abnormal, forceful, fast, or irregular heartbeat. Most are benign, but some signal serious arrhythmias.

A highly lethal malignancy of the pancreas, mostly ductal adenocarcinoma, usually found late and carrying a low survival rate.

Pancreatitis is inflammation of the pancreas, occurring in acute or chronic forms that can impair digestion and blood glucose regulation.

A common neurodegenerative disorder marked by loss of dopamine-producing neurons and abnormal alpha-synuclein aggregation, causing slowness, tremor and rigidity.

A break in the lining of the stomach or duodenum that penetrates the muscularis mucosa, most often caused by Helicobacter pylori infection or NSAID use.

An inflammatory disease of the tooth-supporting tissues that destroys gum attachment and alveolar bone.

Plague is a serious bacterial infection caused by Yersinia pestis, spread mainly by fleas that live on wild rodents. It has caused major historical pandemics and still occurs in parts of the world today.

Pneumonia is an infection that inflames the air sacs of one or both lungs, usually caused by bacteria or viruses, and remains a leading cause of death worldwide.

A trauma- and stressor-related disorder marked by intrusive memories, avoidance, and persistent threat; covers its diagnosis, causes, prevalence, and treatment.

A metabolic state in which blood glucose or HbA1c is raised above normal but below the diagnostic threshold for diabetes.

Prostate cancer is a malignancy of the prostate gland, ranging from slow-growing localized tumors to aggressive metastatic disease.

A chronic, immune-mediated inflammatory skin disease marked by scaly plaques, driven by IL-23/IL-17 signalling and often linked to psoriatic arthritis and other systemic conditions.

A rash is a change in the skin's color, appearance, or texture. It is a symptom with many possible causes, not a single disease.

Rheumatoid arthritis is a chronic autoimmune disease that causes joint inflammation and can damage joints and affect other organs.

Rosacea is a chronic inflammatory skin disorder that mainly affects the central face and is marked by flushing, persistent redness, papules, pustules, and visible blood vessels.

A chronic psychiatric disorder marked by psychosis, negative and cognitive symptoms, and disrupted thinking. Its causes are multifactorial, and treatment can ease symptoms but usually continues over a lifetime.

Scoliosis is a three-dimensional lateral deformity of the spine, most often idiopathic and emerging in adolescence; this entry covers its causes, diagnosis, classification and treatment.

A life-threatening organ dysfunction caused by a dysregulated host response to infection, sepsis is a leading global cause of death and demands rapid recognition and treatment.

Shortness of breath, or dyspnea, is a subjective experience of uncomfortable breathing that can arise from respiratory, cardiac, systemic, or psychological factors.

Sickle cell disease is a group of inherited hemoglobin disorders that cause red blood cell sickling, anemia, painful episodes, and potentially serious organ damage.

Skin cancer is the most common type of cancer, arising from the skin's keratinocytes or melanocytes. Its main forms are basal cell carcinoma, squamous cell carcinoma, and melanoma.

Smallpox was a contagious disease caused by variola virus, eradicated worldwide through vaccination and coordinated surveillance, with eradication formally declared in 1980.

Pain or irritation of the throat, most often caused by viral infection and usually resolving without specific treatment; bacterial causes such as group A streptococcus need antibiotics.

Stomach cancer (gastric cancer) is a malignancy arising in the stomach lining, most often adenocarcinoma, and is strongly linked to chronic Helicobacter pylori infection.

Stroke is sudden brain injury caused by interrupted blood flow or bleeding, potentially resulting in neurological disability or death.

Bleeding into the fluid-filled space surrounding the brain, caused by trauma or spontaneous vascular rupture and associated with potentially severe neurological injury.

Syphilis is a chronic bacterial infection caused by the spirochete Treponema pallidum, usually spread through sexual contact, which can progress over years to damage the skin, nervous system, heart, and other organs if untreated.

A chronic autoimmune disease with variable inflammatory effects on the skin, joints, blood, kidneys, and other organs.

Formation of blood clots within blood vessels or the heart, potentially obstructing circulation or causing embolism.

Thymoma is a rare thymic epithelial tumor with malignant potential and distinctive associations with autoimmune disease.

Tinnitus is the perception of sound without an external source, often associated with hearing loss and sometimes affecting sleep, concentration, and emotional well-being.

A transient ischemic attack is a temporary episode of focal neurological dysfunction caused by inadequate blood flow, without acute tissue infarction, that signals an increased risk of stroke.

Tuberculosis is a contagious bacterial disease, caused mainly by Mycobacterium tuberculosis, that usually affects the lungs and remains a leading infectious cause of death worldwide.

A chromosomal condition involving complete or partial loss of a second sex chromosome, with variable effects on growth, ovarian function, and other organ systems.

Type 1 diabetes is a chronic disease, usually autoimmune, in which destruction of pancreatic beta cells causes severe insulin deficiency and elevated blood glucose.

A chronic metabolic disease marked by insulin resistance, progressive beta-cell dysfunction and persistent hyperglycemia, and the most common form of diabetes worldwide.

An infection of the urinary system, usually bacterial, ranging from bladder infection to kidney infection and systemic illness.

Urticaria (hives) is a common, mast cell–driven skin disorder marked by itchy wheals and/or angioedema, classified as acute or chronic.