(HealthDay News) -- Caffeine is a stimulant, and it can cause side effects when you consume too much.

Some people, the U.S. National Library of Medicine says, should restrict caffeine intake to little or none, including pregnant women, and people with ulcers or heart disease.

If you're cutting back on caffeine, the agency recommends doing so slowly to avoid these potential side effects of caffeine withdrawal:

• Irritability.
• Vomiting.
• Drowsiness.
• Headaches.
• Nausea.

• More News on Caffeine

Related MedlinePlus Pages:

• Caffeine