Here you’ll find 38 Diseases that start with R, organized from “Rabies” to “Rubella”. They range from common viral infections to rare genetic and autoimmune disorders. The list includes clinician-reviewed entries, an internal A–Z index, and source links for further reading.
Diseases that start with R are human medical conditions whose common or clinical names begin with the letter R. Rabies is a notable example with deep historical and cultural impact on public health and vaccination.
Below you’ll find the table with the following columns: Disease, Symptoms, Causes & Risk factors, Treatments & Referral, Notes/Sources.
Disease: The official or most widely used name that lets you identify the condition and perform further searches.
Symptoms: Common signs you may expect, listed briefly so you can recognize or compare clinical presentations quickly.
Causes & Risk factors: Primary causes plus major risk factors or mechanisms to help you understand why the disease occurs.
Treatments & Referral: Typical first-line treatments and when you should seek specialist care or urgent medical attention.
Notes/Sources: Quick clinical notes, alternate names, and links to authoritative guidance for deeper reading and verification.
Diseases that start with R
| Disease | ICD codes | Key symptoms | Causes & treatments |
|---|---|---|---|
| Rabies | A82 | fever, agitation, hydrophobia | Cause: rabies virus from animal bite; Treatment: wound care, vaccine, immunoglobulin, urgent referral |
| Rhabdomyolysis | M62.82 | muscle pain, weakness, dark urine | Cause: muscle breakdown (trauma, exertion, drugs); Treatment: IV fluids, electrolytes, hospital referral |
| Rickets | E55.0 | bowed legs, delayed growth, bone pain | Cause: vitamin D/calcium deficiency; Treatment: vitamin D, calcium, nutrition, pediatric referral |
| Rheumatoid arthritis | M06 | joint pain, morning stiffness, swollen joints | Cause: autoimmune inflammation; Treatment: DMARDs, NSAIDs, rheumatology referral |
| Rheumatic fever | I00 | fever, migratory arthritis, heart murmur | Cause: post‑streptococcal autoimmune reaction; Treatment: antibiotics, anti‑inflammatories, cardiology follow‑up |
| Rheumatic heart disease | N/A | shortness of breath, heart murmur, chest pain | Cause: repeated rheumatic fever; Treatment: antibiotics, valve repair/replacement, cardiology referral |
| Rosacea | L71 | facial redness, bumps/pustules, flushing | Cause: unclear vascular/inflammatory triggers; Treatment: topical agents, oral antibiotics, dermatology referral |
| Rubella | B06 | fever, pink rash, swollen glands | Cause: rubella virus; Treatment: supportive care, vaccination for prevention, obstetric referral if pregnant |
| Rocky Mountain spotted fever | N/A | fever, rash, headache | Cause: Rickettsia from tick bite; Treatment: doxycycline, urgent infectious disease or emergency care |
| Respiratory syncytial virus infection | J21.0 | cough, wheeze, difficulty breathing | Cause: RSV virus; Treatment: supportive care, oxygen, pediatric referral if severe |
| Respiratory distress syndrome (neonatal) | P22.0 | rapid breathing, grunting, cyanosis | Cause: surfactant deficiency in preterm infants; Treatment: surfactant, respiratory support, NICU referral |
| Restless legs syndrome | G25.81 | urge to move legs, nighttime discomfort | Cause: idiopathic or iron deficiency; Treatment: iron, dopaminergic agents, sleep clinic referral |
| Reactive arthritis | M02 | joint pain, eye redness, urinary symptoms | Cause: post‑infectious autoimmune reaction; Treatment: NSAIDs, antibiotics if infection present, rheumatology referral |
| Reye syndrome | G93.7 | vomiting, confusion, seizures | Cause: aspirin use during viral illness; Treatment: ICU care, intracranial pressure management, urgent referral |
| Retinitis pigmentosa | H35.5 | night blindness, peripheral vision loss | Cause: inherited genetic degeneration; Treatment: low‑vision support, genetics referral |
| Retinoblastoma | C69.2 | white pupil, eye swelling, vision loss | Cause: RB1 gene mutation; Treatment: chemotherapy, surgery, oncology/ophthalmology referral |
| Retinopathy of prematurity | N/A | abnormal eye vessels, poor vision | Cause: premature birth and immature retinal vessels; Treatment: laser or anti‑VEGF therapy, neonatal/ophthalmology referral |
| Retinal detachment | H33 | flashes, floaters, sudden vision loss | Cause: retinal tear or trauma; Treatment: surgical repair, urgent ophthalmology referral |
| Renal cell carcinoma | C64 | blood in urine, flank pain, weight loss | Cause: smoking, obesity, genetic factors; Treatment: surgery, targeted therapy, oncology referral |
| Renal failure, chronic | N18 | fatigue, swelling, reduced urine output | Cause: diabetes, hypertension; Treatment: blood pressure control, nephrology, dialysis/transplant when advanced |
| Renal failure, acute | N17 | sudden low urine, swelling, confusion | Cause: dehydration, toxins, obstruction; Treatment: fluids, treat cause, nephrology referral |
| Renovascular hypertension | I15 | high blood pressure, kidney dysfunction | Cause: renal artery stenosis (atherosclerosis/fibromuscular dysplasia); Treatment: BP meds, revascularization, nephrology/vascular referral |
| Rhinitis | N/A | sneezing, nasal congestion, runny nose | Cause: infections or allergies; Treatment: antihistamines, nasal corticosteroids, ENT/allergy referral if chronic |
| Rhinovirus infection (common cold) | J00 | sore throat, runny nose, sneezing | Cause: rhinovirus; Treatment: symptomatic care, fluids, rest |
| Rhinocerebral mucormycosis | N/A | facial pain, black nasal discharge, fever | Cause: invasive fungal infection in immunocompromised; Treatment: urgent antifungal and surgery, infectious disease/ENT referral |
| Raynaud’s phenomenon | I73.0 | cold, pale/blue fingers, numbness | Cause: vascular spasm, cold or autoimmune triggers; Treatment: warming, vasodilators, rheumatology referral |
| Ramsay Hunt syndrome | N/A | facial paralysis, ear pain, vesicles | Cause: varicella zoster virus reactivation; Treatment: antivirals, steroids, ENT/neurology referral |
| Rasmussen encephalitis | N/A | seizures, progressive weakness, cognitive decline | Cause: presumed autoimmune focal brain inflammation; Treatment: immunotherapy, surgery, neurology referral |
| Rhabdomyosarcoma | N/A | painless mass, swelling, bleeding | Cause: malignant tumor of skeletal muscle cells; Treatment: surgery, chemo, oncology referral |
| Relapsing polychondritis | N/A | ear pain, cartilage swelling, joint pain | Cause: autoimmune cartilage inflammation; Treatment: steroids, immunosuppressants, rheumatology referral |
| Rotavirus infection | A08.0 | watery diarrhea, vomiting, fever | Cause: rotavirus; Treatment: oral rehydration, supportive care, pediatric referral if severe |
| Roseola infantum | N/A | high fever then sudden rash, irritability | Cause: human herpesvirus‑6/7; Treatment: supportive care, fever control, pediatric advice |
| Rosai‑Dorfman disease | N/A | painless lymph node swelling, fever, fatigue | Cause: histiocytic proliferation of unclear cause; Treatment: steroids, surgery, hematology/oncology referral if needed |
| Retropharyngeal abscess | J39.0 | throat pain, difficulty swallowing, neck stiffness | Cause: bacterial infection after pharyngitis or trauma; Treatment: IV antibiotics, drainage, ENT referral |
| Rhinosinusitis (acute) | J01.9 | facial pain, nasal congestion, purulent nasal discharge | Cause: viral or bacterial infection; Treatment: saline, decongestants, antibiotics if bacterial, ENT referral if recurrent |
| Rett syndrome | F84.2 | loss of purposeful hand use, repetitive hand wringing | Cause: MECP2 gene mutation; Treatment: supportive therapies, neurology/genetics referral |
| Rickettsiosis (general) | N/A | fever, headache, rash | Cause: various Rickettsia from arthropod bites; Treatment: doxycycline, infectious disease referral |
| Rhizomelic chondrodysplasia punctata | N/A | short limbs, developmental delay, skeletal abnormalities | Cause: peroxisomal metabolic defects; Treatment: supportive care, genetics/metabolic referral |
Descriptions
Rabies
A deadly viral infection affecting the brain and spinal cord after animal exposure. Affects all ages; prompt post‑exposure prophylaxis prevents fatal disease.
Rhabdomyolysis
Rapid muscle-cell breakdown releasing myoglobin that can damage kidneys. Can follow injury, drugs or extreme exercise; early fluids reduce kidney injury.
Rickets
Softening of growing bones in children due to vitamin D or calcium deficiency; prevents normal growth and causes deformities if untreated.
Rheumatoid arthritis
A chronic autoimmune disease causing symmetric joint inflammation, disability, and systemic effects; early treatment improves long‑term outcomes.
Rheumatic fever
An inflammatory complication after strep throat that can damage heart valves in children and young adults; prevention by treating strep reduces risk.
Rheumatic heart disease
Chronic damage to heart valves from prior rheumatic fever, leading to heart failure and arrhythmias years later.
Rosacea
Chronic facial skin condition causing redness, visible blood vessels and sometimes acne‑like bumps; common in adults, can be socially distressing.
Rubella
A usually mild viral illness in children and adults but dangerous in early pregnancy (congenital rubella syndrome); prevented by MMR vaccine.
Rocky Mountain spotted fever
A potentially severe tick‑borne bacterial infection causing fever and rash that can be fatal without prompt doxycycline treatment.
Respiratory syncytial virus infection
A common cause of bronchiolitis and pneumonia in infants and older adults; supportive care and monitoring are key.
Respiratory distress syndrome (neonatal)
A lung condition of premature babies due to immature surfactant causing breathing difficulty; treated in neonatal intensive care.
Restless legs syndrome
A neurological disorder causing uncomfortable leg sensations at rest, often disturbing sleep and quality of life.
Reactive arthritis
Inflammatory arthritis occurring after certain infections (GI/urogenital); can affect joints, eyes and urinary tract.
Reye syndrome
A rare but severe encephalopathy in children linked to aspirin use during viral infections; rapid intensive care is critical.
Retinitis pigmentosa
A group of inherited retinal disorders causing progressive vision loss, often beginning in childhood or young adulthood.
Retinoblastoma
A malignant eye tumor of infants and young children; early detection and treatment preserve life and vision.
Retinopathy of prematurity
A disease of premature infants where abnormal blood vessel growth can lead to retinal detachment and blindness if not treated.
Retinal detachment
Separation of the retina from underlying tissue causing sudden vision changes — an ocular emergency needing prompt surgery.
Renal cell carcinoma
The most common kidney cancer in adults; often discovered by blood in urine or incidentally on imaging.
Renal failure, chronic
Long‑term loss of kidney function that increases cardiovascular risk and may require dialysis or transplant.
Renal failure, acute
A rapid decline in kidney function often reversible if the underlying cause is rapidly treated.
Renovascular hypertension
High blood pressure due to reduced kidney blood flow; treating the blockage can improve blood pressure.
Rhinitis
Inflammation of the nasal mucosa causing congestion and sneezing; includes allergic and non‑allergic forms that affect quality of life.
Rhinovirus infection (common cold)
The typical “common cold” caused by rhinoviruses; self‑limited but highly prevalent and disruptive.
Rhinocerebral mucormycosis
A serious fungal infection (often in diabetics/immunosuppressed) affecting sinuses and brain; requires immediate treatment to reduce mortality.
Raynaud’s phenomenon
Intermittent blood‑flow reduction to fingers/toes causing color changes and pain; can be primary or secondary to autoimmune disease.
Ramsay Hunt syndrome
A shingles-related facial nerve palsy with ear rash that can cause long‑term facial weakness and hearing issues.
Rasmussen encephalitis
A rare progressive brain inflammation in children causing refractory seizures and neurological decline; may require hemispherectomy.
Rhabdomyosarcoma
A malignant soft‑tissue cancer seen mostly in children and adolescents; treatment is multimodal with curative intent.
Relapsing polychondritis
A rare autoimmune disease attacking cartilage (ears, nose, airway) causing recurrent inflammation and potential airway compromise.
Rotavirus infection
A leading cause of severe diarrhea in young children worldwide; vaccination greatly reduces severe cases.
Roseola infantum
A common childhood illness with several days of high fever followed by a pink rash as fever resolves; usually mild.
Rosai‑Dorfman disease
A rare disorder causing massive lymph node enlargement and systemic symptoms; treatment tailored to symptoms and organ involvement.
Retropharyngeal abscess
A deep neck space infection that can obstruct the airway; prompt airway assessment and surgical drainage are often required.
Rhinosinusitis (acute)
Acute inflammation of nasal passages and sinuses causing facial pain and congestion; most cases viral and self‑limited.
Rett syndrome
A neurodevelopmental disorder affecting mostly girls, with regression after initial normal development and lifelong disability.
Rickettsiosis (general)
A group of tick‑ or flea‑borne bacterial infections (including spotted fevers) that can be severe but respond to doxycycline.
Rhizomelic chondrodysplasia punctata
A rare inherited skeletal disorder causing disproportionate short stature and developmental problems; requires specialized multidisciplinary care.