Educational use only: Symptom.Today is an educational tool and does not provide medical advice, diagnosis, or treatment. Results are not a substitute for professional medical care. If symptoms are severe, worsening, or concerning, seek medical attention immediately. In an emergency, call your local emergency number.
DISEASE INTELLIGENCE LIBRARY

Search the body's vocabulary.

Browse hundreds of conditions with symptoms, causes, treatment, and red flags.

NeurologicalModerate

Migraine

Recurrent moderate-to-severe pulsating headaches, often with nausea and light sensitivity.

HeadacheNauseaLight sensitivity
NeurologicalMild

Tension Headache

The most common headache, often felt as a tight band around the head.

HeadacheNeck painNeck stiffness
NeurologicalSerious

Cluster Headache

Severe one-sided headaches around the eye, occurring in clusters over weeks.

HeadacheEye painEye redness
NeurologicalMild

Cervicogenic Headache

Headache referred from problems in the neck — often one-sided and triggered by neck movement.

HeadacheNeck painNeck stiffness
MusculoskeletalMild

Cervical Strain

Muscle or ligament strain in the neck causing stiffness and pain.

Neck painNeck stiffnessHeadache
NeurologicalEmergency

Stroke

Sudden interruption of blood flow to the brain — every minute counts.

Facial droopSlurred speechArm weakness
NeurologicalEmergency

Transient Ischemic Attack

A 'mini-stroke' with brief stroke-like symptoms — a major warning sign.

Facial droopSlurred speechArm weakness
NeurologicalModerate

Concussion

A traumatic brain injury affecting brain function, usually temporary.

HeadacheDizzinessConfusion
NeurologicalSerious

Brain Tumor

Abnormal growth of cells in the brain — symptoms vary by location.

HeadacheBlurred visionConfusion
NeurologicalEmergency

Meningitis

Inflammation of the membranes surrounding the brain and spinal cord — can be life-threatening.

FeverNeck stiffnessNeck pain
NeurologicalEmergency

Encephalitis

Inflammation of the brain itself, often viral — a medical emergency.

FeverConfusionHeadache
NeurologicalSerious

Epilepsy

A neurological disorder causing recurrent unprovoked seizures.

SeizureConfusionMemory loss
NeurologicalEmergency

Subarachnoid Hemorrhage

Bleeding into the space surrounding the brain — classic 'thunderclap' headache.

Thunderclap headacheNeck stiffnessVomiting
NeurologicalModerate

Bell's Palsy

Sudden one-sided facial weakness from inflammation of the facial nerve.

Facial droopFacial painEar pain
NeurologicalSerious

Multiple Sclerosis

An autoimmune disease that damages the protective covering of nerves.

Blurred visionDouble visionArm weakness
NeurologicalSerious

Parkinson's Disease

A progressive nervous system disorder affecting movement.

TremorLoss of balanceWeakness
NeurologicalSerious

Alzheimer's Disease

A progressive disease that destroys memory and other mental functions.

Memory lossConfusion
NeurologicalModerate

Vertigo

A spinning sensation often caused by inner-ear problems.

DizzinessLoss of balanceNausea
MusculoskeletalMild

Carpal Tunnel Syndrome

Compression of the median nerve at the wrist causing tingling and weakness.

Hand tinglingWrist painArm numbness
MusculoskeletalModerate

Sciatica

Pain radiating along the sciatic nerve from the lower back down the leg.

Shooting leg/back painLower back painLeg weakness
EyeMild

Conjunctivitis (Pink Eye)

Inflammation of the eye's outer membrane — viral, bacterial, or allergic.

Eye rednessEye dischargeItchy eyes
EyeMild

Stye

A red, painful lump near the edge of the eyelid.

Eye painSkin swellingEye redness
EyeSerious

Glaucoma

Damage to the optic nerve, often from elevated eye pressure — can cause blindness.

Eye painVision lossBlurred vision
EyeMild

Dry Eye

A common condition where the eyes don't produce enough tears.

Itchy eyesEye rednessBlurred vision
ENTMild

Middle Ear Infection

Infection of the middle ear, common in children.

Ear painEar dischargeFever
ENTMild

Swimmer's Ear

Outer ear canal infection often from trapped moisture.

Ear painEar dischargeItching
ENTMild

Tinnitus

Ringing or buzzing in the ears without an external sound source.

Ringing in earsHearing lossDizziness
RespiratoryMild

Common Cold

A mild viral upper respiratory infection.

Runny noseNasal congestionSore throat
RespiratoryModerate

Influenza (Flu)

A contagious respiratory illness caused by influenza viruses.

FeverMuscle achesFatigue
RespiratoryModerate

COVID-19

Respiratory illness caused by SARS-CoV-2, ranging from mild to severe.

FeverCoughFatigue
RespiratorySerious

Pneumonia

Lung infection causing alveolar inflammation, cough, fever, and breathing difficulty.

Cough with phlegmFeverShortness of breath
RespiratoryMild

Bronchitis

Inflammation of the bronchial tubes — usually viral, sometimes bacterial.

CoughChest painFatigue
RespiratoryModerate

Asthma

Chronic airway inflammation causing wheezing, breathlessness, and chest tightness.

WheezingShortness of breathChest pain
RespiratorySerious

COPD

Chronic obstructive pulmonary disease — progressive airway disease.

Shortness of breathCough with phlegmWheezing
ENTMild

Strep Throat

Bacterial throat infection caused by group A Streptococcus.

Sore throatSwollen tonsilsFever
ENTMild

Tonsillitis

Inflammation of the tonsils, usually viral.

Swollen tonsilsSore throatDifficulty swallowing
ENTMild

Laryngitis

Inflammation of the voice box causing hoarseness.

HoarsenessSore throatCough
ENTMild

Sinusitis

Inflammation of the sinuses, often after a cold.

Nasal congestionFacial painHeadache
ENTMild

Allergic Rhinitis (Hay Fever)

An allergic response causing sneezing, congestion, and itchy eyes.

SneezingRunny noseItchy eyes
RespiratorySerious

Whooping Cough

Highly contagious bacterial respiratory infection.

CoughVomitingFatigue
InfectiousSerious

Tuberculosis

A bacterial infection that mainly affects the lungs.

Cough with phlegmCoughing up bloodUnintended weight loss
CardiacModerate

Angina

Chest pain from reduced blood flow to the heart, often triggered by exertion.

Chest painShortness of breathArm or jaw pain
CardiacEmergency

Heart Attack

Blockage of blood flow to the heart muscle — a life-threatening emergency.

Crushing chest pressureChest painShortness of breath
CardiacModerate

Arrhythmia

Irregular heartbeat — can range from harmless to life-threatening.

PalpitationsRacing heartIrregular pulse
CardiacSerious

Atrial Fibrillation

An irregular, often rapid heart rhythm that increases stroke risk.

Irregular pulsePalpitationsFatigue
CardiacSerious

Pericarditis

Inflammation of the lining around the heart — sharp chest pain that worsens with breathing.

Chest painFeverShortness of breath
CardiacEmergency

Pulmonary Embolism

A blood clot lodged in the pulmonary arteries — can be rapidly fatal.

Shortness of breathChest painRacing heart
CardiacSerious

Heart Failure

The heart can't pump blood as well as it should.

Shortness of breathAnkle swellingFatigue
CardiacModerate

High Blood Pressure

Chronically elevated blood pressure — a major risk factor for stroke and heart attack.

HeadacheDizzinessBlurred vision
CardiacEmergency

Deep Vein Thrombosis

A blood clot in a deep vein, usually in the leg — can travel to the lungs.

Calf painLeg swellingSkin warmth
CardiacEmergency

Aortic Dissection

A tear in the aorta's inner wall — extreme tearing chest/back pain.

Chest painBack painCold sweat
GastrointestinalModerate

Food Poisoning

Illness from contaminated food — usually self-limited but can be severe.

VomitingDiarrheaAbdominal pain
GastrointestinalMild

Gastritis

Inflammation of the stomach lining causing pain and nausea.

Upper stomach painNauseaVomiting
GastrointestinalModerate

Peptic Ulcer

An open sore in the stomach or upper intestine lining.

Upper stomach painNauseaBlack tarry stool
GastrointestinalMild

GERD (Acid Reflux)

Chronic acid reflux that irritates the esophagus.

HeartburnChest painDifficulty swallowing
GastrointestinalEmergency

Appendicitis

Inflammation of the appendix requiring urgent surgical evaluation.

Right lower abdominal painAbdominal painNausea
GastrointestinalModerate

Gallstones

Hardened deposits of digestive fluid in the gallbladder.

Right upper abdominal painNauseaVomiting
GastrointestinalSerious

Hepatitis

Inflammation of the liver, often viral.

Jaundice (yellow skin/eyes)FatigueNausea
GastrointestinalSerious

Pancreatitis

Inflammation of the pancreas — can be acute or chronic.

Upper stomach painBack painVomiting
GastrointestinalMild

Irritable Bowel Syndrome

A functional bowel disorder causing recurring abdominal pain and bowel changes.

Abdominal painBloatingDiarrhea
GastrointestinalSerious

Crohn's Disease

An inflammatory bowel disease causing inflammation of the digestive tract.

Abdominal painDiarrheaBlood in stool
GastrointestinalSerious

Ulcerative Colitis

An inflammatory bowel disease affecting the colon and rectum.

DiarrheaBlood in stoolAbdominal pain
GastrointestinalMild

Gastroenteritis

Inflammation of the stomach and intestines, usually viral.

DiarrheaVomitingAbdominal pain
GastrointestinalMild

Hemorrhoids

Swollen veins in the lowest part of the rectum and anus.

Blood in stoolItchingAbdominal pain
GastrointestinalEmergency

Bowel Obstruction

A blockage in the small or large intestine — needs urgent care.

Abdominal painVomitingBloating
UrinaryMild

Urinary Tract Infection

An infection in any part of the urinary system.

Painful urinationFrequent urinationSudden urge to urinate
UrinarySerious

Kidney Infection

A bacterial infection of one or both kidneys.

Flank painFeverChills
UrinaryModerate

Kidney Stones

Hard mineral deposits forming in the kidneys, causing severe flank pain.

Flank painBlood in urineNausea
Women's HealthMild

Vaginal Yeast Infection

A common fungal infection causing itching and discharge.

ItchingVaginal discharge
Women's HealthMild

Bacterial Vaginosis

An imbalance of vaginal bacteria causing discharge and odor.

Vaginal dischargeItching
Women's HealthSerious

Endometriosis

Tissue similar to the uterine lining grows outside the uterus, causing pain.

Pelvic painHeavy menstrual bleedingAbdominal pain
Women's HealthEmergency

Ectopic Pregnancy

Pregnancy that implants outside the uterus — a medical emergency.

Abdominal painMissed periodPelvic pain
Women's HealthModerate

Ovarian Cyst

A fluid-filled sac on or in an ovary.

Pelvic painAbdominal painBloating
Women's HealthSerious

Pelvic Inflammatory Disease

An infection of the female reproductive organs.

Pelvic painFeverVaginal discharge
Men's HealthEmergency

Testicular Torsion

Twisting of the spermatic cord cutting off blood flow — needs surgery within hours.

Testicular painNauseaVomiting
Men's HealthModerate

Prostatitis

Inflammation of the prostate gland.

Painful urinationPelvic painFrequent urination
SkinMild

Eczema

A chronic itchy inflammatory skin condition.

ItchingRashDry skin
SkinModerate

Psoriasis

An autoimmune skin condition causing thick, scaly plaques.

RashDry skinItching
SkinMild

Allergic Rash

A skin reaction triggered by an allergen — hives, itching, swelling.

HivesItchingSkin redness
SkinMild

Fungal Skin Infection

A superficial fungal infection of the skin — itchy, red, sometimes flaky.

ItchingRashSkin redness
SkinSerious

Cellulitis

A bacterial skin infection causing redness, warmth, and swelling — can spread quickly.

Skin rednessSkin swellingFever
InfectiousModerate

Shingles

A painful blistering rash caused by reactivation of the chickenpox virus.

RashBlistersSkin redness
InfectiousMild

Chickenpox

A highly contagious viral infection causing an itchy, blistering rash.

RashBlistersItching
InfectiousSerious

Measles

A highly contagious viral disease — preventable by vaccination.

FeverRashCough
SkinMild

Scabies

An itchy skin infestation by tiny burrowing mites.

ItchingRashBlisters
SkinMild

Acne

A common skin condition with pimples, blackheads, and inflammation.

RashSkin redness
EmergencyEmergency

Anaphylaxis

A severe, life-threatening allergic reaction.

Throat tightnessLip or tongue swellingHives
AllergyModerate

Food Allergy

An immune reaction to a specific food — can be mild to life-threatening.

HivesItchingLip or tongue swelling
EndocrineSerious

Diabetes

A chronic disease affecting how the body uses glucose.

Excessive thirstFrequent urinationFatigue
EndocrineModerate

Hyperthyroidism

An overactive thyroid producing too much thyroid hormone.

Heat intoleranceUnintended weight lossPalpitations
EndocrineModerate

Hypothyroidism

An underactive thyroid producing too little thyroid hormone.

Cold intoleranceUnintended weight gainFatigue
EndocrineSerious

Adrenal Insufficiency

The adrenal glands don't produce enough cortisol.

FatigueWeaknessUnintended weight loss
MusculoskeletalMild

Lower Back Strain

A pulled or torn muscle in the lower back, often from lifting or twisting.

Lower back painBack stiffness
MusculoskeletalSerious

Rheumatoid Arthritis

An autoimmune disorder causing painful, swollen joints.

Joint painSwollen jointBack stiffness
MusculoskeletalModerate

Osteoarthritis

Wear-and-tear arthritis causing joint pain and stiffness.

Joint painKnee painHip pain
MusculoskeletalModerate

Gout

A form of arthritis from uric acid crystal buildup, often in the big toe.

Joint painSwollen jointSkin redness
MusculoskeletalModerate

Fibromyalgia

Widespread musculoskeletal pain with fatigue and sleep issues.

Muscle achesFatigueInsomnia
MusculoskeletalMild

Plantar Fasciitis

Inflammation of the plantar fascia causing heel and arch pain, worst with first steps.

Foot pain
MusculoskeletalMild

Foot Strain

Overworked muscles or ligaments in the foot, often after long walks or new activity.

Foot painAnkle swelling
MusculoskeletalMild

Tendinitis

Inflammation of a tendon from overuse — common in the foot, ankle, and Achilles.

Foot painJoint painAnkle swelling
MusculoskeletalModerate

Stress Fracture

A small crack in a bone from repetitive force — often in the foot or shin.

Foot painAnkle swelling
NeurologicalModerate

Diabetic Neuropathy

Nerve damage from long-standing diabetes, often felt as burning or numbness in the feet.

Foot painHand tinglingWeakness
GeneralMild

Dehydration

Loss of body fluids causing fatigue, dizziness, and weakness.

FatigueDizzinessWeakness
GeneralModerate

Anemia

Low red blood cell count causing fatigue and weakness.

FatigueWeaknessShortness of breath
EmergencyEmergency

Sepsis

A life-threatening response to infection — call 911 if suspected.

FeverConfusionRacing heart
InfectiousMild

Mononucleosis

Viral infection often called 'mono', causing prolonged fatigue.

FatigueSore throatSwollen lymph nodes
InfectiousModerate

Lyme Disease

A tick-borne bacterial infection — early treatment is important.

RashFatigueJoint pain
InfectiousMild

Viral Infection (Generic)

A general viral illness with fever, fatigue, and body aches.

FeverFatigueMuscle aches
Mental HealthModerate

Anxiety Disorder

Excessive worry that interferes with daily life — often with physical symptoms.

RestlessnessRacing heartFeeling anxious
Mental HealthModerate

Panic Disorder

Recurrent unexpected panic attacks with intense physical symptoms.

Panic attacksRacing heartShortness of breath
Mental HealthSerious

Depression

Persistent feelings of sadness and loss of interest affecting daily life.

Depressed moodFatigueInsomnia
Mental HealthSerious

Post-Traumatic Stress Disorder

A mental health condition triggered by experiencing a terrifying event.

InsomniaFeeling anxiousPanic attacks