Some other possible culprits include stress and caffeine, among many others.

Risks include smoking, caffeine, alcohol use, and illicit drug use.

For this reason, many over-the-counter headache drugs include caffeine in their formula.

Ingredients include glucose, caffeine from green coffee beans and guarana.

The original formulation's active ingredients included caffeine, ginseng and Guarana.

For some, no drug use includes caffeine which is a stimulant drug.

Correlations of mental disorders with drug use include cannabis, alcohol and caffeine.

These combination products also include paracetamol (acetaminophen) and caffeine.

Its ingredients include green tea extracts, caffeine, calcium and artificial sweeteners.

Possible causes include stress, too much caffeine, and other health problems.