Symptoms by Body System
Common symptoms organized by the body system they affect, with information on possible causes and when to seek medical attention.
🧠 Head & Neurological
Symptoms affecting the brain, nerves, and sensory organs including headaches, dizziness, vision changes, and cognitive issues.
Common Symptoms
- Headache — Tension headaches (band-like pressure), migraines (throbbing, often one-sided), cluster headaches, sinus headaches
- Dizziness — Lightheadedness, vertigo (spinning sensation), unsteadiness, faintness
- Vision changes — Blurry vision, double vision, floaters, flashing lights, temporary vision loss
- Numbness/Tingling — Pins and needles, loss of sensation, typically in hands, feet, or face
- Memory problems — Forgetfulness, difficulty concentrating, confusion
- Fatigue — Persistent tiredness not relieved by rest
Possible Causes
Tension, stress, dehydration, lack of sleep, migraines, medication side effects, inner ear problems (vertigo), blood pressure changes, infections, neurological conditions, vision problems requiring correction.
⚠️ Seek Immediate Care If:
- Sudden, severe headache ("worst headache of your life")
- Headache with fever, stiff neck, rash, or confusion
- Sudden vision loss or double vision
- Sudden numbness or weakness on one side of body (stroke warning)
- Sudden difficulty speaking or understanding speech
- Seizure or loss of consciousness
🫁 Respiratory
Symptoms affecting breathing, lungs, and airways including cough, shortness of breath, and congestion.
Common Symptoms
- Cough — Dry cough, productive cough (with mucus), chronic cough lasting 3+ weeks
- Shortness of breath — Difficulty breathing, rapid breathing, feeling like you can't get enough air
- Wheezing — High-pitched whistling sound when breathing
- Congestion — Stuffy nose, sinus pressure, postnasal drip
- Sore throat — Pain, scratchiness, difficulty swallowing
- Chest tightness — Pressure or constriction in the chest area
Possible Causes
Common cold, flu, COVID-19, allergies, asthma, bronchitis, pneumonia, GERD (acid reflux), smoking, environmental irritants, anxiety.
⚠️ Seek Immediate Care If:
- Severe difficulty breathing or feeling like you're suffocating
- Blue lips, fingernails, or skin (cyanosis)
- Coughing up blood
- Chest pain with breathing
- High fever (over 103°F/39.4°C) with respiratory symptoms
- Rapid worsening of breathing difficulty
❤️ Cardiovascular
Symptoms related to the heart and blood vessels including chest discomfort, palpitations, and swelling.
Common Symptoms
- Chest pain/discomfort — Sharp, dull, pressure, squeezing, burning sensations
- Palpitations — Racing heart, skipped beats, fluttering, pounding
- Swelling — Edema in ankles, feet, legs, or abdomen
- Fatigue — Unusual tiredness with exertion
- Shortness of breath — Especially with activity or lying flat
- Lightheadedness — Feeling faint, especially when standing
Possible Causes
Anxiety, muscle strain, acid reflux, caffeine, dehydration, arrhythmias, high blood pressure, heart disease, heart valve problems, heart failure, peripheral artery disease.
⚠️ Seek Immediate Care If:
- Chest pain or pressure lasting more than a few minutes
- Chest discomfort with shortness of breath, sweating, nausea, or arm/jaw pain
- Sudden severe palpitations with dizziness or fainting
- Sudden swelling in one leg (possible blood clot)
- Severe, sudden shortness of breath
🫃 Digestive
Symptoms affecting the stomach, intestines, and digestive tract including pain, nausea, and bowel changes.
Common Symptoms
- Abdominal pain — Cramping, sharp, dull, or burning pain anywhere in the belly
- Nausea/Vomiting — Feeling sick to stomach, throwing up
- Diarrhea — Loose, watery stools, increased frequency
- Constipation — Infrequent bowel movements, hard stools, straining
- Bloating — Feeling of fullness, distended abdomen, gas
- Heartburn — Burning sensation in chest/throat after eating
Possible Causes
Food poisoning, viral gastroenteritis, food intolerances, IBS, GERD, ulcers, gallstones, appendicitis, inflammatory bowel disease, medication side effects, stress.
⚠️ Seek Immediate Care If:
- Severe abdominal pain that prevents standing upright
- Vomiting blood or material that looks like coffee grounds
- Blood in stool or black, tarry stools
- Severe dehydration (no urination, extreme thirst, confusion)
- Abdominal pain with high fever
- Sudden, severe bloating with inability to pass gas
🦴 Musculoskeletal
Symptoms affecting bones, joints, muscles, and connective tissues including pain, stiffness, and weakness.
Common Symptoms
- Joint pain — Aching, stiffness, swelling in joints (knees, hips, shoulders, fingers)
- Back pain — Lower back, upper back, or neck pain; sharp or dull
- Muscle aches — Soreness, cramps, spasms, weakness
- Stiffness — Reduced range of motion, especially in morning
- Swelling — Inflammation around joints or injury sites
- Weakness — Difficulty with strength or endurance
Possible Causes
Overuse, strain, injury, poor posture, arthritis (osteoarthritis, rheumatoid), fibromyalgia, tendinitis, bursitis, herniated disc, osteoporosis, infections.
⚠️ Seek Immediate Care If:
- Sudden, severe pain after injury with obvious deformity
- Inability to bear weight on a limb
- Hot, red, swollen joint with fever (possible infection)
- Back pain with loss of bladder/bowel control
- Numbness or weakness spreading down arms or legs
- Pain in calf with swelling (possible blood clot)
🩹 Skin
Symptoms affecting the skin, hair, and nails including rashes, itching, and color changes.
Common Symptoms
- Rash — Red, bumpy, scaly, blistering, or spreading skin changes
- Itching — Localized or widespread urge to scratch
- Hives — Raised, itchy welts that come and go
- Dry skin — Flaking, cracking, roughness
- Lumps/bumps — New growths, moles, or skin changes
- Color changes — Yellowing, darkening, pale patches, bruising
Possible Causes
Allergic reactions, contact dermatitis, eczema, psoriasis, infections (fungal, bacterial, viral), insect bites, medication reactions, sun exposure, dry climate, autoimmune conditions.
⚠️ Seek Immediate Care If:
- Rash spreading rapidly with fever
- Hives with difficulty breathing or swelling of face/throat
- Signs of severe infection: increasing redness, warmth, pus, red streaks
- Sudden, widespread skin peeling
- New mole or changing mole (asymmetry, irregular border, multiple colors, growing)
- Skin turning blue, gray, or mottled