Although we do not know what causes IIH, we have many clues. The condition occurs mostly in women in the childbearing years. The symptoms often start or worsen during a period of weight gain. The disease is rare in thin men. This has led some researchers to look for hormonal changes within the body. To date no consistent changes in hormones have been found. As a part of our research program, we are trying to find some hormonal changes in a newly discovered hormone.

Although no associated conditions besides recent weight gain are usually found, many conditions have been linked to high intracranial pressure. Any disorder that blocks the flow of spinal fluid between the brain and its route to the blood, the jugular vein, can cause raised pressure. For example, scarring cells next to the brain that absorb the spinal fluid (the arachnoid granulations) can cause raised pressure. Similarly, blood clots in the veins draining the brain can cause increased intracranial pressure. Withdrawal of steroids, large doses of vitamin A or intake of foods containing considerable vitamin A (such as liver), use of body building-type steroids and possibly certain drugs such as tetracycline and lithium can cause raised intracranial pressure. These conditions can mimic IIH.