Is caffeine dangerous?

Caffeine has a powerful effect on the body. It can boost energy and alertness, which explains why some people can’t start their day without a cup of coffee.

As long as you drink it in moderation, caffeine isn’t dangerous. Most people can safely consume up to 400 milligrams of caffeine a day. (That’s about four 8-ounce cups of coffee.) But other people are more sensitive to caffeine. If they consume too much, they may experience:

  • restlessness
  • insomnia
  • headaches
  • abnormal heart rhythm

The effects of caffeine sensitivity are bothersome, but relatively minor. This isn’t the case for people who have a caffeine allergy. If you live with this allergy, consuming the smallest amount of caffeine can have a negative impact on your physical and mental health.

Physical symptoms of a caffeine allergy are similar to those caused by other food allergies. For example:

  • mouth, tongue, or lip itchiness
  • swollen lips or tongue
  • hives

These symptoms may begin shortly after consuming caffeine, or develop hours after exposure. Since caffeine allergies aren’t as well known, you may equate symptoms with another type of allergy.

A severe caffeine allergy can also produce anaphylaxis symptoms. Anaphylaxis symptoms include:

  • difficulty breathing because of swollen throat or tongue
  • wheezing
  • coughing

Symptoms of caffeine sensitivity are trigged by a sudden rush of adrenaline. People with a caffeine intolerance metabolize caffeine slowly.

A caffeine allergy develops when the immune system perceives caffeine as a harmful invader. The immune system produces the antibody immunoglobulin E. The antibody then travels to your cells, causing allergy symptoms.

Learn more: Allergic reactions »

Caffeine allergies are difficult to diagnose because they are so rare.

A skin test may be performed to diagnose a caffeine allergy. During your appointment, your doctor places trace amounts of the allergen on your arm, and then monitors your arm for a reaction. Developing redness, itchiness, or pain at the test site may confirm a caffeine allergy.

If you experience physical symptoms of a caffeine allergy, stop ingesting any food or drink that might contain caffeine and contact your doctor right away. Your doctor may advise you to take an over-the-counter antihistamine which may reduce symptoms such as itchiness, swelling, and hives. But the only way to prevent a caffeine allergy is avoiding foods and drinks containing caffeine.

It’s important to read food and drink labels.

If you rely on caffeine for an energy boost, consider other ways to naturally boost your energy and stay alert. For example:

Increase physical activity

Start a workout routine and exercise for a minimum of 150 minutes each week. Jog, walk, ride a bike, or take a workout class.

Get plenty of sleep

Sleeping less than seven to nine hours a night can cause morning fatigue. Create a comfortable sleep environment and establish a regular bedtime routine. Turn off the TV and other electronic devices, and make sure your room is a comfortable temperature and dark.

Take vitamin supplements

Some vitamins can naturally boost energy levels over time. These include B vitamins, tyrosine, and rhodiola rosea. Talk to your doctor before starting a vitamin regiment, especially if you’re taking prescription medicine.

If you have a caffeine allergy and continue to ingest caffeine, your symptoms can worsen. And depending on the severity of a reaction, you may develop anaphylaxis symptoms, which can be life-threatening.

If you get a proper diagnosis and avoid caffeine, your symptoms should improve. Giving up caffeine can trigger withdrawal symptoms, such as headaches, fatigue, and shakiness. But these symptoms are short-term and typically resolve within a week.