list of side effects of tramadol 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. main article: tramadol 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)