(HealthDay News) — Millions of Americans rely on caffeine for a morning or afternoon energy boost.

However, relying too much on caffeine can cause unpleasant side effects such as migraines, stomach aches and irritability, says Mayo Clinic.

Signs you should curb caffeine use are:

  • You drink more than four cups per day.
  • You’re losing sleep.
  • You’re taking medication.

A safe amount of caffeine is usually under 400 milligrams per day, or less than four cups of coffee, Mayo says.

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