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Clinical & Layman Language Dictionary (Deduplicated A–Z)

Medical Terms & Simple Meanings A–Z

Search over 153+ verified medical terms. Clear layman definitions, clinical explanations, frequency ratings (⭐⭐⭐ Very Common), pronunciations, and body system tags.

Showing 68 Medical Terms Reset Filters
Gastrointestinal⭐⭐ Common

Abdominal Distension

/ab-DOM-i-nuhl dih-STEN-shuhn/
Simple Meaning:

Enlargement or noticeable swelling of the abdomen.

Physical expansion of the abdominal cavity due to trapped intestinal gas, fluid accumulation (ascites), or tissue swelling.

Gastrointestinal⭐⭐ Common

Ascites

/uh-SYE-teez/
Simple Meaning:

Buildup of fluid inside the abdominal cavity.

Accumulation of serous fluid within the peritoneal cavity, most commonly caused by hepatic portal hypertension and liver cirrhosis.

Neurological⭐⭐ Common

Ataxia

/uh-TAK-see-uh/
Simple Meaning:

Poor voluntary muscle coordination or balance.

Neurological sign consisting of lack of voluntary coordination of muscle movements, often due to cerebellar lesions or sensory loss.

Musculoskeletal⭐⭐ Common

Atrophy

/AT-ruh-fee/
Simple Meaning:

Wasting or shrinking of body tissue or muscle.

Decrease in size or cell mass of a tissue or organ due to disuse, aging, malnourishment, or denervation.

Neurological⭐⭐ Common

Anosmia

/an-OZ-mee-uh/
Simple Meaning:

Loss of the sense of smell.

Inability to perceive odors, commonly caused by nasal inflammation, viral upper respiratory infections, or head trauma.

Respiratory⭐⭐ Common

Apnea

/AP-nee-uh/
Simple Meaning:

Temporary cessation of breathing.

Transient pause in respiration lasting longer than 10 seconds, frequently seen during sleep (obstructive sleep apnea).

General Medical⭐⭐ Common

Benign

/bih-NYNE/
Simple Meaning:

Not cancerous or harmful.

Refers to a neoplasm or condition that does not metastasize, invade local tissues, or pose a malignant threat.

General Medical⭐⭐ Common

Bilateral

/bye-LAT-er-uhl/
Simple Meaning:

Affecting both sides of the body.

Anatomical designation indicating symmetry or involvement of both left and right paired structures (e.g. bilateral lung crackles).

Hematology⭐⭐ Common

Bilirubin

/bil-ih-ROO-bin/
Simple Meaning:

Yellow pigment from broken down red blood cells.

Heme degradation product processed by the liver; elevated serum levels cause scleral icterus and cutaneous jaundice.

Dermatological⭐⭐ Common

Blanching

/BLAN-ching/
Simple Meaning:

Temporary skin whitening when pressed.

Transitory paleness produced by local capillary compression, used clinically to assess capillary refill time and rash types.

Musculoskeletal⭐⭐ Common

Bone Pain

/bohn payn/
Simple Meaning:

Pain felt inside or originating from bones.

Deep, aching skeletal pain caused by trauma, osteomyelitis, bone density loss, or metastatic lesions.

Gastrointestinal⭐⭐ Common

Cirrhosis

/sih-ROH-sis/
Simple Meaning:

Irreversible scarring of liver tissue.

End-stage liver disease characterized by fibrous septa surrounding regenerative hepatic nodules, causing portal hypertension.

Systemic⭐⭐ Common

Clammy

/KLAM-ee/
Simple Meaning:

Cool, moist, and sweaty skin.

Physical finding indicating sympathetic vasoconstriction and diaphoresis, seen in cardiogenic shock, hypoglycemia, or severe pain.

Emergency⭐⭐ Common

Collapse

/kuh-LAPS/
Simple Meaning:

Sudden loss of physical strength or consciousness.

Abrupt postural breakdown resulting from acute syncope, severe cardiac arrhythmia, or vasovagal episode.

Gastrointestinal⭐⭐ Common

Colicky Pain

/KOL-ik-ee payn/
Simple Meaning:

Severe pain that comes and goes in rhythmic waves.

Paroxysmal cramping pain caused by smooth muscle spasm in hollow viscera attempting to bypass an obstruction (e.g. ureteral or biliary colic).

General Medical⭐⭐ Common

Congenital

/kuhn-JEN-ih-tuhl/
Simple Meaning:

Present at or before birth.

Medical trait, anomaly, or disorder existing at birth due to genetic or intrauterine factors.

Neurological⭐⭐ Common

Convulsion

/kuhn-VUL-shuhn/
Simple Meaning:

Involuntary violent muscle shaking or contractions.

Paroxysmal motor manifestation of abnormal excessive synchronous cerebral cortical electrical discharges during seizures.

Neurological⭐⭐ Common

Delirium

/dih-LEER-ee-uhm/
Simple Meaning:

Sudden, acute disturbance in attention and awareness.

Fluctuating organic mental syndrome involving acute cognitive dysfunction, sleep-wake cycle alteration, and visual hallucinations.

Systemic⭐⭐ Common

Diaphoresis

/dye-uh-fuh-REE-sis/
Simple Meaning:

Medical term for excessive, unprovoked sweating.

Profuse sweating triggered by sympathetic nervous system stimulation, associated with acute MI, severe pain, or hypoglycemia.

Neurological⭐⭐ Common

Diplopia

/dih-PLOH-pee-uh/
Simple Meaning:

Medical term for double vision.

Perception of a single object as two images, resulting from extraocular muscle imbalance, cranial nerve palsies, or corneal opacity.

Neurological⭐⭐ Common

Disorientation

/dis-or-ee-uhn-TAY-shuhn/
Simple Meaning:

Difficulty knowing time, place, or personal identity.

Impairment in cognitive orientation regarding time, space, or person, indicative of acute encephalopathy or delirium.

Systemic⭐⭐ Common

Exhaustion

/ig-ZAW-stchuhn/
Simple Meaning:

State of extreme physical or mental tiredness.

Profound physical depletion resulting from severe systemic illness, prolonged physical overexertion, or heat strain.

Dermatological⭐⭐ Common

Ecchymosis

/ek-ih-MOH-sis/
Simple Meaning:

Medical term for a large area of bruising under skin.

Subcutaneous purpuric skin hemorrhage > 1 cm in diameter, evolving from blue-black to yellow-green as hemoglobin breaks down.

Dermatological⭐⭐ Common

Fissure

/FISH-er/
Simple Meaning:

Deep, narrow crack or tear in skin or mucous membrane.

Linear ulceration of mucosal membrane, most commonly occurring in the posterior midline of the anal canal.

Cardiovascular⭐⭐ Common

Flushing

/FLUSH-ing/
Simple Meaning:

Sudden redness and warmth of the skin.

Transient erythema of the face, neck, and upper chest resulting from cutaneous vasodilation, emotional stress, or nitrate drugs.

Gastrointestinal⭐⭐ Common

Flatulence

/FLATCH-uh-luhns/
Simple Meaning:

Release of intestinal gas through the anus.

Passage of rectal gas consisting of nitrogen, oxygen, carbon dioxide, hydrogen, and methane produced by colonic bacterial fermentation.

Neurological⭐⭐ Common

Gait Abnormality

/gayt ab-nor-MAL-ih-tee/
Simple Meaning:

Unusual or unsteady walking pattern.

Deviation from normal biomechanical walking cycle, classified as antalgic, ataxia, spastic steppage, or parkinsonian festinating gait.

Systemic⭐⭐ Common

Generalized Pain

/JEN-er-uh-lyzd payn/
Simple Meaning:

Pain felt across many different areas of the body.

Diffuse musculoskeletal pain affecting multiple anatomical quadrants, characteristic of fibromyalgia or systemic viral illness.

Neurological⭐⭐ Common

Generalized Weakness

/JEN-er-uh-lyzd WEEK-nis/
Simple Meaning:

Loss of physical strength affecting the whole body.

Global reduction in neuromuscular motor force, requiring distinction between true paresis and systemic asthenia.

Respiratory⭐⭐ Common

Hemoptysis

/hee-MOP-tih-sis/
Simple Meaning:

Coughing up blood or blood-stained mucus.

Expectorated blood originating from the bronchial arteries or pulmonary parenchyma, signaling lung disease or pulmonary embolism.

Gastrointestinal⭐⭐ Common

Hemorrhoids

/HEM-uh-roidz/
Simple Meaning:

Swollen, inflamed veins around the anus or rectum.

Vascular cushions in the anal canal that become pathologically engorged, causing painless bleeding or painful thrombosis.

Respiratory⭐⭐ Common

Hypoxia

/hye-POK-see-uh/
Simple Meaning:

Low oxygen levels in body tissues.

Deficiency in oxygen supply reaching tissues despite adequate blood flow, assessed via arterial blood gas or pulse oximetry.

ENT⭐⭐ Common

Hoarseness

/HORS-nis/
Simple Meaning:

Rough, raspy, or weak voice.

Dysphonia caused by irregular vocal cord vibration due to laryngitis, vocal nodules, or recurrent laryngeal nerve palsy.

General Medical⭐⭐ Common

Irritation

/ir-ih-TAY-shuhn/
Simple Meaning:

Discomfort caused by inflammation or physical exposure.

Localized superficial inflammatory tissue reaction caused by mechanical friction, chemical agents, or thermal injury.

General Medical⭐⭐ Common

Localized Pain

/LOH-kuhl-yzd payn/
Simple Meaning:

Pain strictly limited to one specific body area.

Nociceptive pain circumscribed to a distinct anatomical site without regional radiation.

Neurological⭐⭐ Common

Lethargy

/LETH-er-jee/
Simple Meaning:

Severe lack of energy and reduced alertness.

Pathological drowsiness or apathy characterized by slowness, listlessness, and delayed response to stimuli.

General Medical⭐⭐ Common

Lesion

/LEE-zhuhn/
Simple Meaning:

Area of abnormal or damaged tissue.

Generic pathological term denoting any circumscribed area of tissue damage caused by injury, ulceration, or tumor.

General Medical⭐⭐ Common

Malignant

/muh-LIG-nuhnt/
Simple Meaning:

Cancerous and capable of invading nearby tissues.

Refers to neoplasms displaying cellular atypia, uncontrolled growth, local tissue invasion, and capacity for distant metastasis.

General Medical⭐⭐ Common

Mass

/mas/
Simple Meaning:

Abnormal lump or collection of tissue.

Volumetric tissue expansion detected during physical examination or diagnostic CT/MRI radiology.

Respiratory⭐⭐ Common

Nasal Discharge

/NAY-zuhl DIS-charj/
Simple Meaning:

Fluid or mucus draining from the nose (Rhinorrhea).

Secretion of watery, mucoid, or purulent fluid from nostrils, seen in rhinitis and sinusitis.

Gastrointestinal⭐⭐ Common

Odynophagia

/oh-din-oh-FAY-jee-uh/
Simple Meaning:

Severe, painful swallowing.

Pain experienced during deglutition, commonly caused by esophageal ulceration, candidiasis, or severe pharyngitis.

Cardiovascular⭐⭐ Common

Orthopnea

/or-THOP-nee-uh/
Simple Meaning:

Difficulty breathing when lying flat.

Dyspnea occurring in recumbent position, relieved by sitting upright, characteristic of left-sided heart failure.

Neurological⭐⭐ Common

Paresthesia

/pair-es-THEE-zee-uh/
Simple Meaning:

Tingling or "pins and needles" sensation.

Abnormal spontaneous cutaneous sensation occurring without external physical stimulus.

Neurological⭐⭐ Common

Paralysis

/puh-RAL-ih-sis/
Simple Meaning:

Complete loss of muscle movement.

Loss of voluntary motor function in one or more muscle groups caused by central or peripheral neural lesion.

Neurological⭐⭐ Common

Paresis

/puh-REE-sis/
Simple Meaning:

Partial muscle weakness or incomplete loss of movement.

Slight or partial paralysis characterized by reduced muscle strength rather than complete motor loss.

Hematology⭐⭐ Common

Petechiae

/puh-TEE-kee-ee/
Simple Meaning:

Tiny pinpoint red spots of bleeding under skin.

Non-blanching subcutaneous hemorrhagic spots < 2 mm caused by capillary fragility or thrombocytopenia.

ENT⭐⭐ Common

Pharyngitis

/fair-in-JYE-tis/
Simple Meaning:

Inflammation of the throat (sore throat).

Inflammatory infection of pharyngeal mucosa caused by Group A Streptococcus or respiratory viruses.

Neurological⭐⭐ Common

Photophobia

/foe-toe-FOE-bee-uh/
Simple Meaning:

Unusual sensitivity or intolerance to light.

Ocular discomfort or pain produced by light exposure, seen in corneal abrasions, uveitis, and migraine.

Respiratory⭐⭐ Common

Pleuritic Pain

/ploor-IT-ik payn/
Simple Meaning:

Sharp chest pain that worsens with deep breathing.

Sharp stabbing pain resulting from friction between inflamed visceral and parietal pleural layers during respiration.

Dermatological⭐⭐ Common

Pustule

/PUS-tyool/
Simple Meaning:

Small skin lesion containing yellow pus.

Small circumscribed epidermal elevation filled with neutrophils and purulent exudate.

Hematology⭐⭐ Common

Purpura

/PUR-pyoo-ruh/
Simple Meaning:

Purple-red skin spots caused by bleeding under skin.

Non-blanching hemorrhagic skin lesions measuring 3–10 mm, resulting from vasculitis or bleeding disorders.

Neurological⭐⭐ Common

Radiating Pain

/RAY-dee-ay-ting payn/
Simple Meaning:

Pain spreading outward from its origin to another area.

Pain traveling along a anatomical dermatome or nerve tract distant from the primary site of tissue injury.

Neurological⭐⭐ Common

Referred Pain

/rih-FURD payn/
Simple Meaning:

Pain felt in a body location away from its actual source.

Nociceptive sensation perceived at a site distant from the affected visceral organ due to shared spinal cord nerve roots.

General Medical⭐⭐ Common

Recurrent

/rih-KUR-uhnt/
Simple Meaning:

Happening repeatedly over time.

Medical events or disease episodes that return after periods of clinical remission.

Gastrointestinal⭐⭐ Common

Retching

/RECH-ing/
Simple Meaning:

Repeated, involuntary attempts to vomit without expelling contents.

Spasmodic respiratory and abdominal muscle contractions accompanying nausea prior to or following emesis.

Neurological⭐⭐ Common

Rigidity

/rih-JID-ih-tee/
Simple Meaning:

Abnormal involuntary muscle stiffness or hardness.

Hypertonia displaying constant uniform resistance to passive joint stretch (Lead-pipe or Cogwheel rigidity).

Neurological⭐⭐ Common

Stabbing Pain

/STAB-ing payn/
Simple Meaning:

Very sharp, intense, piercing pain.

Paroxysmal lancinating pain characteristic of neuralgia or visceral perforation.

Emergency⭐⭐ Common

Stridor

/STRY-dor/
Simple Meaning:

Harsh, high-pitched breathing sound on inspiration.

High-pitched monophonic sound caused by turbulent airflow through a narrowed extrathoracic upper airway.

Cardiovascular⭐⭐ Common

Syncope

/SIN-kuh-pee/
Simple Meaning:

Temporary loss of consciousness (fainting).

Transient loss of consciousness and postural tone with spontaneous recovery, caused by global cerebral hypoperfusion.

Respiratory⭐⭐ Common

Tachypnea

/tak-ip-NEE-uh/
Simple Meaning:

Abnormally rapid breathing rate.

Elevated respiratory frequency (> 20 breaths/min in adults) compensating for metabolic acidosis or hypoxemia.

Gastrointestinal⭐⭐ Common

Ulcer

/UL-ser/
Simple Meaning:

Open sore caused by skin or tissue breakdown.

Circumscribed loss of cutaneous or mucosal epithelium extending into dermis or submucosa.

General Medical⭐⭐ Common

Unilateral

/yoo-nih-LAT-er-uhl/
Simple Meaning:

Affecting only one side of the body.

Anatomical designation indicating involvement restricted to either the left or right side.

Emergency⭐⭐ Common

Unconsciousness

/uhn-KON-shuhs-nis/
Simple Meaning:

Lack of awareness and responsiveness.

State of profound loss of cognitive awareness and motor reactivity to external sensory stimuli.

Neurological⭐⭐ Common

Unsteady Gait

/uhn-STED-ee gayt/
Simple Meaning:

Walking with poor balance or coordination.

Irregular, wide-based, or staggering walking pattern caused by vestibular, cerebellar, or sensory nerve deficits.

Dermatological⭐⭐ Common

Urticaria

/ur-tih-KAIR-ee-uh/
Simple Meaning:

Medical term for itchy, raised hives.

Vascular reaction of skin characterized by transient erythematous wheals accompanied by pruritus.

General Medical⭐⭐ Common

Warmth

/wormth/
Simple Meaning:

Increased temperature felt in an area.

Physical finding of hyperthermia in cutaneous tissue signaling local vasodilation and inflammation.

Dermatological⭐⭐ Common

Wheal

/weel/
Simple Meaning:

Raised, temporary area of itchy skin swelling.

Transient edematous papule or plaque characteristic of urticarial allergic reactions.

General Medical⭐⭐ Common

Wound

/woond/
Simple Meaning:

Damage or break in body tissue or skin.

Disruption of anatomical integrity of skin or organ tissue caused by mechanical trauma or surgery.

This information is educational only and does not replace professional medical advice.