Advil is one of the brand-name versions of ibuprofen. You may know that it relieves minor aches, pains, and fever. However, you may not know the side effects of this drug. Learn what these effects are and when they’re most likely to happen so that you can use this drug safely.

Ibuprofen helps lower fever. It also helps relieve minor pain from:

  • headaches
  • toothaches
  • menstrual cramps
  • backaches
  • muscle aches

Ibuprofen belongs to a group of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). These drugs temporarily reduce the amount of substances that your body makes called prostaglandins. Your body releases prostaglandins when you have an injury. These substances contribute to inflammation, which includes swelling, fever, and increased sensitivity to pain.

Ibuprofen is so widely used that it can be easy to forget this drug can cause side effects. Still, ibuprofen is a drug, and like any drug, it comes with risks. The more common side effects of ibuprofen are:

  • stomach pain
  • heartburn
  • nausea
  • vomiting
  • gas
  • constipation
  • diarrhea

Not everyone has these side effects. When they do happen, the effects are usually mild. Many people can prevent these side effects by taking ibuprofen with milk or food.

However, serious side effects can happen. Most of these risks are uncommon and can usually be avoided by taking ibuprofen as recommended. However, taking too much ibuprofen or taking it for too long can make these serious side effects more likely. These side effects include:

Heart attack and stroke

The risks of heart attack and stroke are rare for most people. However, your risks increase if you use higher dosages than recommended or use ibuprofen for too long. Your risk is also higher if you:

  • have other risk factors for heart attack or stroke
  • have a clotting disorder
  • take other medications that affect how your blood clots

If you have any risk factors or take other drugs, talk to your doctor before using ibuprofen.

Decreased kidney function and increased blood pressure

Prostaglandins help keep the pressure in your kidneys at the right level to filter the fluids in your body and maintain your blood pressure.

Ibuprofen changes your body’s production of prostaglandins. This change can lead to an imbalance in your body fluid pressure, which can decrease your kidney function and increase your blood pressure. Symptoms of decreased kidney function include:

  • increased blood pressure
  • fluid buildup
  • dehydration
  • urinating less frequently
  • dizziness

Your risk is increased if you:

  • are an older adult
  • have kidney disease
  • take blood pressure medications

Stomach and intestine ulcers and bleeding

Prostaglandins also help maintain the constant repair of your stomach lining, which protects you from damage from stomach acid. Because ibuprofen decreases how much prostaglandin you make, stomach damage such as bleeding and ulcers in the stomach and intestines is a possible side effect.

The risk of this side effect is fairly rare. However, the risk increases the longer you use ibuprofen. Other factors that increase your risk include:

  • a history of ulcers or bleeding in your stomach or intestine
  • older age
  • use of anticoagulants (blood thinners) or oral steroids
  • smoking
  • alcohol use, specifically more than three alcoholic drinks per day

Allergic reaction

Some people have an allergic reaction to ibuprofen. This is rare.

If you’ve had allergic reactions to aspirin, don’t take ibuprofen. If you start to have trouble breathing or your face or throat starts to swell, contact your doctor right away and stop taking ibuprofen.

Liver failure

There is a very rare risk of liver failure from taking ibuprofen. If you have liver disease, talk to your doctor before taking ibuprofen. Stop taking ibuprofen and contact your doctor right away if you start to have any of the following symptoms:

  • nausea
  • tiredness
  • lack of energy
  • itchiness
  • yellowing of your skin or the whites of your eyes
  • pain in the upper right area of your abdomen
  • flu-like symptoms

These may be signs of liver damage or liver failure.

Ibuprofen can be a safe and easy over-the-counter remedy for minor aches and pains. However, if you don’t use it as recommended, ibuprofen can possibly be harmful.

It’s always smart to talk to your doctor before taking ibuprofen if you’re not sure if you should use it. If you experience bothersome side effects or believe you may have taken too much, contact your doctor right away.

Most of the serious side effects happen from taking the drug when you shouldn’t, taking too much of it, or taking it for too long. You can reduce your risk of side effects by using the smallest possible dose for shortest possible time.