Ibuprofen is a pain reliever known as an NSAID, or a non-steroidal anti-inflammatory drug. According to Drugs.com, most people can take up to 800 mg of ibuprofen four times a day without serious complications. Higher doses of ibuprofen can cause symptoms of overdose.
Gastrointestinal Symptoms
An overdose of ibuprofen can cause damage to a person's gastrointestinal tract and upset the stomach, according to the National Institutes of Health (NIH). Nausea, vomiting, stomach pain, diarrhea, indigestion and bleeding---either throwing up blood or blood in the stool---may all be signs that someone has ingested more of the medication than is recommended.
Auditory and Visual Changes
People who have taken too much ibuprofen may have blurred vision and can experience ringing in the ears, a condition called tinnitus. A study reported in the November 1986 issue of "Annals of Emergency Medicine" found that involuntary movements of the eyes, called nystagmus, is also a symptom consistent with NSAID overdose.
Breathing Difficulties
Breathing difficulties may signify an overdose of ibuprofen is in progress. Patients may wheeze, experience breathing interruptions or have a very slow breathing pattern, as reported by the NIH. A dangerously low blood pressure level, called hypotension, may accompany breathing problems.
Neurological Symptoms
Doses of ibuprofen that exceed 3200 mg daily can cause neurological symptoms, including mental confusion, altered states of consciousness including coma, headaches, dizziness and an extreme feeling of fatigue. The study in "Annals of Emergency Medicine" reported that a few cases of ibuprofen overdose led to seizures.
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. Large quantities of the drug, even if not classified an overdose, can cause kidney damage in some people and should not be used by people with pre-existing kidney disease, according to Drugs.com.
Reduced Motor Skills
Unsteadiness, slowness in movement and not being able to speak coherently may all be signs of ibuprofen overdose.
