Overview

Do you often feel sick after drinking coffee? You may think you’re allergic, but chances are it’s something else. Only around 4 percent of Americans have food allergies. Most people are likely experiencing what’s called food sensitivity, which can produce similar symptoms. Here’s what you need to know if you suspect you may be allergic or sensitive to coffee.

The symptoms of an allergic reaction to coffee may be severe. It may affect one or more of your body’s systems, like the circulatory system, digestive system, or respiratory system. Your reaction will likely occur within two hours of drinking coffee, and it can also get worse over time.

Symptoms might include:

  • vomiting
  • stomach cramping
  • hives
  • wheezing or shortness of breath
  • trouble swallowing
  • fainting or dizziness
  • pale or blue skin
  • cough
  • weak pulse

Seek medical attention right away if you notice any of these signs, especially if you have more than one of these symptoms at the same time. In rare cases, you may experience anaphylaxis. This life-threatening condition can affect your breathing, heart rate, and blood pressure all at once.

A sensitivity to coffee may make you feel unwell, but it typically doesn’t pose any danger to your overall health. For example, coffee can make heartburn and acid reflux symptoms worse. The caffeine may relax your lower esophageal sphincter, allowing acid to irritate your esophagus.

You may also have unpleasant symptoms if you’re drinking too much coffee.

These include:

  • insomnia
  • nervousness
  • irritability
  • upset stomach
  • elevated heartbeat
  • muscle tremors

Most people who feel sick after drinking coffee may be sensitive to the caffeine. Doctors recommend adults limit caffeine consumption to 400 milligrams per day or less. That’s the amount of caffeine in about four eight-ounce cups of coffee. More than 500 to 600 milligrams may make you feel jittery or give you other side effects. People who don’t normally drink much caffeine may even feel symptoms after drinking just one cup.

If caffeine alone isn’t making you feel sick, you may get a reaction from other ingredients in your beverage. Over 90 percent of people who have food allergies have reactions to one of the following foods:

  • eggs
  • peanuts
  • tree nuts
  • milk
  • fish
  • shellfish
  • wheat
  • soy

The milk or creamer you’re using may be causing your symptoms. If you’re drinking a coffee beverage flavored with syrups, one of the ingredients in the syrup could also be causing your symptoms. When in doubt, it’s best to ask what else besides coffee beans might be inside your brew.

Caffeine allergies are very rare. Allergic responses have been seen among coffee workers, but the reactions seem to be in response to the dust from green coffee beans, as opposed to the consumption of a coffee beverage.

In an older study, scientists explain that there are very few reports of people being allergic to coffee. One male did have symptoms of anaphylaxis within 30 minutes of drinking coffee starting at age nine. When they examined him, his blood test was positive in response to caffeinated coffee and caffeinated cola. That might suggest that he was allergic to the caffeine in the coffee as opposed to the coffee itself.

Otherwise, there isn’t much information about how many people may have an allergy or sensitivity to coffee or caffeine. A small study suggests that men are more sensitive to caffeine than women.

Check labels of your favorite foods carefully. Caffeine may be in other foods and beverages like:

  • black and green teas
  • soda
  • cocoa powder and chocolate
  • energy drinks

The type of coffee you choose may also affect how you react to the drink.

For example, an eight-ounce serving of coffee contains around 94.8 milligrams of caffeine. A one-ounce serving of espresso, on the other hand, packs a whopping 63.6 milligrams of caffeine. If you choose a double shot of espresso, you’d be consuming over 127 milligrams in a very short amount of time. Darker roast coffee often has less caffeine than lighter roasts. The longer the beans are roasted, the more the caffeine level bakes off.

Otherwise, if you know you have sensitivities or allergies to specific foods, ask your barista exactly what’s in that fancy mixed beverage. You may be better off sticking with black coffee and avoiding potential allergens in syrups, milks, and other add-ins.

If you think you have a sensitivity to caffeine, try drinking less coffee or cutting it from your diet entirely. Visit your doctor if your symptoms don’t improve or if your symptoms worsen. There may be something else in your diet or another medical condition that needs attention.

People dealing with acid reflux can also experiment with coffee to see how it affects them. It may trigger more reflux in some people. One study suggests that light roast coffees may aggravate acid reflux symptoms more than darker roasts. That’s because darker roasts contain a substance that may block the stomach from producing excess acid. If you’re unsure whether or not coffee triggers your reflux, ask your doctor.

Learn more: Coffee vs. tea for GERD »

If you are allergic to coffee, reaction signs usually show up within two hours after coming in contact with the allergen. The severity of your reaction may vary depending on your exposure, so it’s important to treat any side effects seriously.

Symptoms of anaphylaxis range from just feeling strange to hives to cardiac arrest. Symptoms may progress quickly, so seek immediate medical attention. If you have other food allergies, ask your doctor about an epinephrine pen, which can help you in case of emergencies.

There’s little information on allergies to roasted coffee. If you have symptoms like irritability or upset stomach, you may only have a sensitivity to coffee or caffeine. You may want to avoid or limit foods with caffeine.

Another option is to try drinking coffee substitutes as part of your morning ritual. Here are a few other warm beverages you may want to try:

  • Herbal teas are available in many flavors. They are warm and satisfying without the caffeine.
  • Rooibos is another type of caffeine-free tea that has a bolder flavor.
  • Roasted corn, barley, or rice teas have earthy and robust flavor without caffeine.
  • White coffee is a Lebanese drink made with a splash of orange blossom water mixed into a cup of boiling water.
  • Ginger honey lemon tonic is especially great when you have a cold. Combine hot water, chopped ginger root, fresh lemon juice, and honey.

Decaffeinated coffee is another option, though these coffees still contain five or fewer milligrams of caffeine per cup. You may have heard that the decaffeination process uses powerful, carcinogenic solvents. Today’s processes are typically safe.