This list includes 46 Diseases that start with D, from “Dandruff” to “Dystonia”. Entries range from common, mild conditions to rare, serious disorders. They are useful for quick reference, patient education, and initial clinical review.
Diseases that start with D are human medical conditions whose names begin with the letter D. For example, “Diphtheria” helped shape modern vaccination programs.
Below you’ll find the table with Disease, Symptoms, Causes, Treatments, and Notes.
Disease name: Short, standard disease name used in clinical practice and literature, so you can identify the condition quickly.
Symptoms: Key signs and symptoms (2–4 items) that help you recognize typical presentations at a glance.
Causes: Primary causes and common risk factors summarized in one or two lines for quick clinical context.
Treatments: First-line and typical treatment options listed, with common care pathways, referral suggestions, and follow-up considerations.
Notes: Brief clinical notes, clinician-review status, and source links to guide your deeper research or follow-up.
Diseases that start with D
| Name | ICD-10/ICD-11 code(s) | Key symptoms | Typical causes / risk factors |
|---|---|---|---|
| Dandruff | L21.0, ED90.1 | Flaky white scalp, itchy scalp, greasy scalp skin | Fungal overgrowth (Malassezia); genetics; stress; oily skin |
| Dandy-Walker syndrome | Q03.1, LA02.1 | Slow motor development, large head size, poor coordination, vomiting | Congenital brain malformation; genetic factors; environmental exposures during pregnancy |
| Darier’s disease | Q82.8, EC30.2 | Warty skin blemishes, thick or split nails, rash in skin folds | Genetic mutation (ATP2A2 gene); autosomal dominant inheritance |
| De Quervain’s tenosynovitis | M65.4, FB51.3 | Thumb-side wrist pain, swelling near thumb base, difficulty gripping | Repetitive strain or overuse; hormonal changes; pregnancy; arthritis |
| Deep vein thrombosis (DVT) | I82.40, BD71.1 | Leg swelling, leg pain or tenderness, red or warm skin on leg | Blood clot formation; immobility; major surgery; cancer; genetic clotting disorders |
| Degenerative disc disease | M51.3, FA80.0 | Chronic low back pain, pain radiating to legs, numbness or tingling | Aging and wear-and-tear; genetics; spinal injury; lifestyle factors |
| Dehydration | E86.0, 5D31 | Thirst, dark yellow urine, fatigue, dizziness | Insufficient fluid intake; excessive fluid loss (sweating, vomiting, diarrhea) |
| Delirium | F05, 6D70 | Acute confusion, attention problems, fluctuating awareness, disorientation | Underlying illness (infection, metabolic); surgery; medication side effects; drug withdrawal |
| Delusional disorder | F22, 6A24 | Persistent non-bizarre delusions, minimal other psychosis | Unknown; genetic factors; neurological factors; stress |
| Dementia | F03, 6D86 | Memory loss, difficulty problem-solving, confusion, personality changes | Brain cell damage (e.g., Alzheimer’s, stroke); genetics; age; lifestyle |
| Dementia with Lewy bodies | G31.83, 6D81 | Cognitive fluctuations, visual hallucinations, parkinsonism symptoms | Lewy body protein deposits in the brain; age; genetic factors |
| Dengue fever | A90, 1D01.0 | High fever, severe headache, severe joint and muscle pain, rash | Viral infection (Dengue virus); transmitted by Aedes mosquitoes |
| Dental caries | K02.9, DA08.0 | Toothache, tooth sensitivity, visible holes or pits in teeth | Bacterial acid production; sugary foods and drinks; poor oral hygiene |
| Depression (Major Depressive Disorder) | F32.9, 6A70 | Persistent low mood, loss of interest or pleasure, fatigue, sleep changes | Complex mix of genetic; biological; environmental; psychological factors |
| Dermatitis herpetiformis | L13.0, EB40.1 | Intensely itchy blisters, rash on elbows or knees, burning sensation | Autoimmune response to gluten; strong association with celiac disease |
| Dermatomyositis | M33.1, 4A41.1 | Progressive muscle weakness, distinctive skin rash, trouble swallowing | Autoimmune disorder; unknown triggers; associated with some cancers |
| Developmental coordination disorder | F82, 6A04 | Clumsiness, poor coordination, difficulty with motor tasks | Neurodevelopmental; unknown exact cause; often co-occurs with other disorders |
| Diabetes insipidus | E23.2, 5A60.0 | Extreme thirst, frequent urination, producing large amounts of diluted urine | Problems with antidiuretic hormone (ADH); kidney damage; genetic factors; brain injury |
| Diabetes mellitus | E11.9, 5A14 | Increased thirst, frequent urination, unexplained weight loss, fatigue | Insulin resistance (Type 2); autoimmune destruction of insulin cells (Type 1) |
| Diabetic ketoacidosis (DKA) | E10.10, 5A21.0 | Nausea and vomiting, abdominal pain, fruity-scented breath, rapid breathing | Severe lack of insulin; infection; missed insulin doses in Type 1 diabetes |
| Diabetic nephropathy | E11.21, 5A12.00 | Swelling in legs and feet, protein in urine, worsening blood pressure | Long-term high blood sugar; high blood pressure; genetic predisposition |
| Diabetic neuropathy | E11.40, 5A12.10 | Numbness in feet or hands, tingling or burning pain, muscle weakness | Nerve damage from high blood sugar; long duration of diabetes |
| Diabetic retinopathy | E11.319, 9B71.0 | Blurry vision, floaters in vision, vision loss, dark spots | Damage to blood vessels of the retina; long-term high blood sugar |
| Diaper dermatitis | L22, EK01 | Red rash on buttocks, irritated skin in diaper area, fussiness in infants | Prolonged wetness or friction; chemical irritation; yeast or bacterial infection |
| DiGeorge syndrome | D82.1, LD2B.0 | Heart defects, frequent infections, developmental delay, distinct facial features | Genetic (deletion on chromosome 22); typically not inherited |
| Diphtheria | A36, 1B91 | Sore throat, thick gray membrane in throat, swollen neck glands, fever | Bacterial infection (Corynebacterium diphtheriae); spread via respiratory droplets |
| Disc herniation | M51.2, FA80.1 | Radiating arm or leg pain, numbness or tingling, muscle weakness | Age-related wear and tear; lifting heavy objects improperly; trauma |
| Discoid lupus erythematosus | L93.0, EE40.0 | Scaly disc-shaped sores, scarring, sores on scalp and face | Autoimmune disorder; sunlight exposure is a major trigger |
| Disseminated intravascular coagulation (DIC) | D65, 3B23 | Widespread bleeding, bruising, blood clots, low blood pressure | Complication of another condition; severe infection (sepsis); trauma; cancer |
| Dissociative identity disorder | F44.81, 6B64 | Presence of two or more distinct identities, memory gaps, personal distress | Response to severe trauma; typically from early childhood abuse |
| Diverticulitis | K57.92, DD90.31 | Severe abdominal pain, fever, nausea, change in bowel habits | Inflammation or infection of diverticula; low-fiber diet; aging; obesity |
| Diverticulosis | K57.90, DD90.30 | Often no symptoms, mild cramps, bloating, constipation | Low-fiber diet; genetics; age; lack of exercise |
| Down syndrome | Q90, LD40.0 | Distinct facial appearance, intellectual disability, developmental delays | Genetic (Trisomy 21); having an extra copy of chromosome 21 |
| Dracunculiasis | B72, 1F64 | Painful skin blister, emerging worm from skin, intense burning pain | Parasitic infection (Dracunculus medinensis); drinking contaminated water |
| Dressler syndrome | I24.1, BC41.0 | Chest pain, fever, fatigue, shortness of breath | Autoimmune response; follows heart attack; heart surgery; or cardiac injury |
| Dry eye syndrome | H04.12, 9A10.0 | Eye dryness, gritty sensation, burning or stinging, blurred vision | Decreased tear production; increased tear evaporation; aging; medical conditions |
| Duchenne muscular dystrophy | G71.0, 8C71.00 | Progressive muscle weakness, frequent falls, difficulty walking, large calf muscles | Genetic mutation (dystrophin gene); X-linked recessive inheritance |
| Dumping syndrome | K91.1, DD91.0 | Nausea, cramping, diarrhea, dizziness, rapid heart rate after eating | Complication of gastric surgery; rapid passage of food into the small intestine |
| Dupuytren’s contracture | M72.0, FB53.0 | Knots of tissue under skin, fingers pulled toward palm, limited hand function | Unknown; genetic predisposition; risk factors include age, male sex, Northern European ancestry |
| Dysentery | A09, 1A0Z | Bloody diarrhea, abdominal cramps, fever, nausea | Bacterial or parasitic infection; Shigella bacteria or Entamoeba histolytica |
| Dyshidrotic eczema | L30.1, EE11.2 | Small itchy blisters, rash on hands and feet, peeling skin | Unknown; associated with stress; allergies; moist hands and feet |
| Dyslexia | F81.0, 6A03.0 | Difficulty reading, trouble spelling words, slow reading speed, mispronouncing words | Neurodevelopmental; genetic factors; differences in brain processing language |
| Dysmenorrhea | N94.6, GA34.0 | Painful menstrual cramps, lower abdominal pain, back pain, headache | Uterine contractions (primary); underlying conditions like endometriosis (secondary) |
| Dyspareunia | F52.6, GA31 | Pain during intercourse, pain after sex, deep pelvic pain | Physical causes (vaginal dryness, injury, infection); psychological factors (anxiety, stress) |
| Dysthymia | F34.1, 6A71.0 | Chronic low mood, low self-esteem, poor concentration, hopelessness | Complex mix of genetic; biological; environmental; psychological factors |
| Dystonia | G24, 8A03 | Involuntary muscle contractions, repetitive movements, abnormal postures | Genetic; brain damage (stroke, trauma); medication side effect; unknown |
Descriptions
Dandruff
A common, mild form of seborrheic dermatitis causing scalp flaking. Affects the skin. Not contagious but can be persistent. Managed with medicated shampoos.
Dandy-Walker syndrome
A rare congenital malformation involving the cerebellum and surrounding fluid-filled spaces. Affects the brain. Severity varies widely. Management often involves surgery to relieve pressure.
Darier’s disease
A rare genetic skin disorder causing persistent greasy, warty papules on the skin. Symptoms typically appear in adolescence. Treatment aims to manage symptoms with creams and medications.
De Quervain’s tenosynovitis
Inflammation of tendons on the thumb side of the wrist, causing pain and tenderness. Affects the musculoskeletal system. Managed with rest, splints, and corticosteroid injections.
Deep vein thrombosis (DVT)
A serious condition where a blood clot forms in a deep vein, usually in the leg. Can lead to a life-threatening pulmonary embolism. Requires urgent care with anticoagulant medications.
Degenerative disc disease
An age-related condition where spinal discs break down, causing pain and sometimes weakness. Affects the spine. Very common. Managed with physical therapy, pain relief, and sometimes surgery.
Dehydration
A condition where the body loses more fluid than it takes in, impairing normal body functions. Can range from mild to life-threatening. Treatment is rehydration, oral or intravenous.
Delirium
An abrupt change in the brain that causes mental confusion and emotional disruption. Common in hospitalized older adults. A medical emergency requiring treatment of the underlying cause.
Delusional disorder
A psychiatric condition where a person holds one or more firm, false beliefs (delusions) for at least one month without other prominent psychotic symptoms. Managed with therapy and antipsychotics.
Dementia
A general term for a progressive decline in cognitive function that interferes with daily life. Alzheimer’s disease is the most common cause. Management focuses on support and slowing progression.
Dementia with Lewy bodies
A type of progressive dementia with features of both Alzheimer’s and Parkinson’s disease. Affects the brain. Requires careful medication management due to sensitivities.
Dengue fever
A mosquito-borne viral illness common in tropical and subtropical areas. Can progress to a severe, life-threatening form. Treatment is supportive care; prevention is key.
Dental caries
Also known as cavities or tooth decay, it is the permanent damage to a tooth’s hard surface. Extremely common. Prevented by good hygiene and treated by dentists with fillings.
Depression (Major Depressive Disorder)
A common and serious mood disorder causing persistent feelings of sadness and loss of interest. Affects mood and daily function. Treatable with therapy, medication, or both.
Dermatitis herpetiformis
An intensely itchy, blistering skin rash that is a direct manifestation of celiac disease. Affects the skin. Managed with a strict gluten-free diet and medication to control symptoms.
Dermatomyositis
A rare inflammatory disease marked by muscle weakness and a characteristic skin rash, often on the face, knuckles, and chest. Affects muscles and skin. Treatment involves immunosuppressants.
Developmental coordination disorder
Also known as dyspraxia, it’s a condition affecting physical coordination in children and adults. Affects motor skills. Managed with occupational and physical therapy to improve function.
Diabetes insipidus
A rare disorder causing an imbalance of fluids in the body, leading to intense thirst and heavy urination. Not related to diabetes mellitus. Treatment depends on the underlying cause.
Diabetes mellitus
A group of metabolic diseases where blood sugar levels are high over a prolonged period. Affects millions worldwide. Managed with lifestyle changes, oral medications, or insulin.
Diabetic ketoacidosis (DKA)
A life-threatening complication of diabetes, primarily Type 1, where the body produces high levels of blood acids called ketones. A medical emergency requiring hospitalization.
Diabetic nephropathy
Kidney damage that results from diabetes, and a leading cause of kidney failure. Affects the kidneys. Management focuses on controlling blood sugar and blood pressure.
Diabetic neuropathy
A type of nerve damage that can occur with diabetes. Most commonly affects nerves in the legs and feet. Managed with blood sugar control and medications for nerve pain.
Diabetic retinopathy
An eye complication of diabetes and a leading cause of blindness in adults. Affects the retina. Early detection and management of diabetes can prevent vision loss.
Diaper dermatitis
Also known as diaper rash, it’s a common form of skin inflammation in the diaper area of infants. Treated by keeping the area clean, dry, and using barrier creams.
DiGeorge syndrome
A chromosomal disorder resulting in poor development of several body systems. Also called 22q11.2 deletion syndrome. Severity varies. Requires a multidisciplinary medical team for management.
Diphtheria
A serious bacterial infection affecting the mucous membranes of the nose and throat. Can be life-threatening. Now rare in many countries due to widespread vaccination (DTaP vaccine).
Disc herniation
A problem with one of the rubbery cushions (discs) between the vertebrae. Also called a slipped or ruptured disc. Often treated with physical therapy and pain medication.
Discoid lupus erythematosus
A chronic autoimmune skin condition of the lupus spectrum that primarily affects the skin. Characterized by inflamed sores that can cause scarring. Managed with sun protection and topical steroids.
Disseminated intravascular coagulation (DIC)
A rare but serious condition where blood clots form throughout the body’s small vessels, using up clotting factors and leading to massive bleeding. A medical emergency.
Dissociative identity disorder
A complex psychiatric condition characterized by a fragmentation of identity into distinct personality states. Formerly multiple personality disorder. Treatment involves long-term psychotherapy.
Diverticulitis
Inflammation or infection of small pouches (diverticula) that can form in the intestines. Common in older adults. Can be serious and may require antibiotics or surgery.
Diverticulosis
The presence of small pouches (diverticula) in the intestinal wall, without inflammation. Very common, especially after age 40. A high-fiber diet is the primary management strategy.
Down syndrome
A genetic condition causing developmental and intellectual delays. The most common chromosomal disorder. Individuals can lead fulfilling lives with support and early intervention services.
Dracunculiasis
Also known as Guinea-worm disease, a parasitic infection nearing eradication. A long worm emerges from the skin over several weeks. Prevention is through safe drinking water.
Dressler syndrome
A type of pericarditis (inflammation of the sac surrounding the heart) that occurs weeks to months after heart damage. Treated with anti-inflammatory medications like aspirin or colchicine.
Dry eye syndrome
A common condition where the eyes don’t produce enough quality tears to stay lubricated. Affects the eyes. Managed with artificial tears, lifestyle adjustments, and prescription drops.
Duchenne muscular dystrophy
A severe type of muscular dystrophy that primarily affects boys, characterized by rapid muscle degeneration. Treatment is supportive, aiming to control symptoms and maximize quality of life.
Dumping syndrome
A condition where food moves too quickly from the stomach to the small intestine. Common after bariatric or stomach surgery. Managed with dietary changes like smaller, more frequent meals.
Dupuytren’s contracture
A hand deformity where tissue under the palm skin thickens and forms a cord, pulling fingers into a bent position. Affects the hands. Treatment may involve injections or surgery.
Dysentery
An intestinal inflammation, especially in the colon, that can lead to severe diarrhea with mucus or blood. Spread through contaminated food or water. Requires medical treatment.
Dyshidrotic eczema
A skin condition causing small, fluid-filled blisters on the palms, fingers, and soles of the feet. Also known as pompholyx. Managed with topical steroids and moisturizers.
Dyslexia
A common learning disorder involving difficulty reading due to problems identifying speech sounds and decoding words. Not related to intelligence. Managed with specialized educational support.
Dysmenorrhea
The medical term for painful periods or menstrual cramps. Extremely common. Managed with pain relievers (NSAIDs), heat application, and sometimes hormonal contraceptives.
Dyspareunia
The medical term for persistent or recurrent genital pain that occurs just before, during or after intercourse. Affects both men and women. Treatment addresses the underlying cause.
Dysthymia
Also known as Persistent Depressive Disorder, it’s a chronic form of depression where a low mood occurs for at least two years. Treatable with psychotherapy and medication.
Dystonia
A movement disorder characterized by sustained muscle contractions causing abnormal, often repetitive, movements or postures. Can affect one muscle or the whole body. Treated with medications or Botox.