Ibuprofen is a pain reliever known as an NSAID, or non-steroidal anti-inflammatory drug 2. According to Drugs.com, most people can take up to 800 milligrams of ibuprofen four times a day without serious complications 2. Higher doses of ibuprofen can cause symptoms of overdose 12. If you experience any adverse effects while taking ibuprofen, consult with a medical professional 2.

Gastrointestinal Symptoms

Auditory and Visual Changes

Taking too much ibuprofen can cause blurred vision and ringing in the ears, a condition called tinnitus 2. A study reported in the November 1986 issue of the "Annals of Emergency Medicine" found that involuntary movements of the eyes, called nystagmus, is also a symptom consistent with NSAID overdose 3.

Breathing Difficulties

Breathing difficulties may signify an overdose of ibuprofen is in progress 12. Patients may wheeze, experience breathing interruptions or have a very slow breathing pattern, notes MedlinePlus. A dangerously low blood pressure level, called hypotension, may accompany breathing problems.

Neurological Symptoms

Doses of ibuprofen that exceed 3200 milligrams daily can also cause neurological symptoms such as mental confusion, altered states of consciousness including coma, as well as headaches, dizziness and an extreme feeling of fatigue 2. The study in "Annals of Emergency Medicine" reported that a few cases of ibuprofen overdose led to seizures 123.

Urinary Problems

Urinating very little, not being able to produce any urine at all, or passing blood in the urine can all be signs of an ibuprofen overdose 12. Large quantities of the drug, even if not classified an overdose, can cause kidney damage in some people and should not be used by those with pre-existing kidney disease, according to Drugs.com 2.

Reduced Motor Skills

Unsteadiness, slowness in movement and not being able to speak coherently may all be signs of ibuprofen overdose 12.