List of side effects of tramadol

The most common side effects of tramadol in order of decreasing incidence are:  Note: Serious adverse effects are in bold.

Very common (>10% frequency)

 * Dizziness
 * Nausea
 * Constipation
 * Vertigo
 * Headache
 * Vomiting
 * Somnolence (drowsiness)

Common (1–10% frequency)

 * Agitation
 * Anxiety
 * Emotional lability
 * Euphoria
 * Nervousness
 * Spasticity
 * Dyspepsia (indigestion)
 * Asthenia (weakness)
 * Pruritus (itchiness)
 * Dry mouth
 * Diarrhea
 * Fatigue
 * Sweating
 * Malaise
 * Vasodilation (dilation (widening) of blood vessels)
 * Confusion
 * Coordination disturbance
 * Miosis
 * Sleep disorder
 * Rash
 * Hypertonia
 * Abdominal pain
 * Weight loss
 * Visual disturbance
 * Flatulence
 * Menopausal symptoms
 * Urinary frequency
 * Urinary retention (being unable to urinate)

Uncommon (0.1-1% incidence)

 * Cardiovascular regulation anomalies (palpitation, tachycardia, postural hypotension or cardiovascular collapse)
 * Retching
 * Gastrointestinal irritation (a feeling of pressure in the stomach, bloating)
 * Urticaria (hives)
 * Trembling
 * Flushing

Rare (0.01–0.1% incidence)

 * Bradycardia
 * Hypertension (high blood pressure)
 * Allergic reactions (e.g. dyspnoea (shortness of breath), bronchospasm, wheezing, angioneurotic oedema)
 * Anaphylaxis
 * Changes in appetite
 * Paraesthesia (pins and needles)
 * Hallucinations
 * Tremor
 * Respiratory depression
 * Epileptiform convulsions
 * Involuntary muscle contractions
 * Abnormal coordination
 * Syncope (fainting)
 * Blurred vision
 * Dyspnoea (shortness of breath)
 * Tinnitus (ringing in the ears)
 * Migraine
 * Stevens–Johnson syndrome/toxic epidermal necrolysis (potentially fatal skin reactions)
 * Motorial weakness
 * Creatinine increase
 * Elevated liver enzymes
 * Hepatitis (liver swelling)
 * Stomatitis (mouth swelling)
 * Liver failure
 * Pulmonary oedema (fluid in the lungs)
 * Gastrointestinal bleeding
 * Pulmonary embolism
 * Myocardial ischaemia (lack of blood supply to the heart muscles)
 * Speech disorders
 * Haemoglobin decrease
 * Proteinuria (protein in the urine; usually indicative of kidney damage)