Key takeaways:
Angioedema is a swelling of the face, neck, and mouth. Angiotensin-converting enzyme (ACE) inhibitors are a group of common blood pressure medications that can cause angioedema.
Angioedema from ACE inhibitors can happen at any time — even if you have taken this medication for years. It often occurs in separate episodes, with weeks or months between the episodes.
Many cases of angioedema resolve on their own. But more severe episodes can affect your airway and lead to life-threatening breathing difficulties.
In the U.S., 40 million people take angiotensin-converting enzyme (ACE) inhibitors, like lisinopril and enalapril, to treat high blood pressure. In fact, ACE inhibitors make up about one-third of all prescribed blood pressure medications. But many people who take these medications aren’t always aware of the risk of angioedema.
Less than 1% of people who take ACE inhibitors will develop angioedema. But given the large number of people who take ACE inhibitors, there’s a good chance ACE inhibitor-induced angioedema will affect you or someone you know. And since this side effect can be life-threatening, it’s important to know how to recognize the early signs.
What is angioedema from ACE inhibitors?
Angioedema is a medical term that refers to swelling in the deeper layers of the skin and tissues. It most commonly affects your face, mouth, throat, and neck. Many people are familiar with this type of swelling as a sign of a severe allergic reaction called anaphylaxis. But angioedema from ACE inhibitors isn’t a true allergy. It’s a side effect that can look like an allergic reaction.
Angioedema from ACE inhibitors happens because these medications cause higher levels of a protein called bradykinin. Bradykinin is a natural part of your body’s inflammatory processes, and it can cause swelling. Most of the time, your body naturally breaks down bradykinin. But some people break it down less efficiently than others. This can put them at higher risk for angioedema.
Who is at risk for angioedema from ACE inhibitors?
Anyone who takes ACE inhibitors can develop angioedema. But some people are at increased risk. This risk is particularly high among African Americans, who are seven times more likely to develop angioedema. Other risk factors include:
Previous episodes of angioedema
A history of seasonal allergies or drug-induced rash
Being older than 65 years
Female sex
Heart failure or coronary heart disease
Certain medications, like gliptins for diabetes or mTOR inhibitors used after a kidney transplant
Symptoms of angioedema from ACE inhibitors
The symptoms of angioedema can vary from person to person. Most often, it starts with swelling of the lips, tongue, or face.
There are several characteristics of the swelling that are unique to angioedema:
Nonsymmetric: Usually the swelling starts on one side of the face or mouth. It’s rarely the same on both sides (symmetric).
Non-pitting: When you push down on the swollen areas, it doesn’t leave a finger impression, or dent.
Non-dependent: The swelling doesn’t get worse because of gravity, like swelling in the lower legs can.
No accompanying itching or hives: This can help you tell angioedema from a typical allergic reaction. Other types of angioedema and allergic reactions can cause itching and have a pronounced rash.
Sometimes, the swelling can be severe and affect your airway. Life-threatening symptoms include:
Hoarseness: Swelling deeper down in your throat can affect your voice. Other people may notice this change before you do.
Difficulty breathing: You may struggle to get air in or out of your lungs.
Stridor: This is a high-pitched noise in your throat that you can hear when breathing in.
Airway blockage: Sometimes swelling in your throat can block your airway. This affects about 1 in 10 people who have angioedema from ACE inhibitors.
While less common, sometimes angioedema can affect the lining of your gastrointestinal (GI) tract. Instead of causing swelling in visible areas like your face, it leads to swelling in your gut.
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Because this swelling is less obvious, it can be harder to identify and diagnose.
Symptoms of a swollen GI tract include:
Vomiting
Decreased appetite
Ascites, or swelling in your abdomen
Timing of symptoms
You can develop angioedema at any time while you’re taking an ACE inhibitor. About half of people who develop angioedema do so within the first week of starting the ACE inhibitor. But it can also happen after taking the medication for months or even years.
Other important factors about timing include:
Episodic: This means the swelling comes and goes. You can have periods of swelling that are separated by long periods without symptoms.
Onset within minutes to hours: The swelling can start and get worse relatively quickly. In some cases the swelling can develop more slowly.
Resolves within 1 to 3 days: For most people, the swelling goes away within a few days, whether or not they discontinue the medication.
Symptoms that get worse: Angioedema tends to become more frequent and more severe with later episodes.
How do you diagnose angioedema from ACE inhibitors?
A healthcare professional can diagnose angioedema from ACE inhibitors based on your symptoms. There’s no specific test to diagnose it.
Angioedema in the lining of your GI tract can be trickier to diagnose. If you’re taking an ACE inhibitor and have symptoms like vomiting or abdominal pain, imaging tests often help. In these cases, a healthcare professional may recommend an ultrasound or CT scan of your abdomen.
How do you treat angioedema from ACE inhibitors?
The first step to treating angioedema caused by ACE inhibitors is to stop the medication. If you don’t stop the medication, episodes of swelling can happen more often. And they can be more severe. Sometimes, swelling can occur for several months even after you stop taking the ACE inhibitor.
There’s some disagreement among experts whether additional treatments can help decrease the swelling. Researchers are studying a couple of different treatments, but it’s not clear if they’re helpful:
Bradykinin receptor antagonists: Examples include icatibant and ecallantide. These are expensive medications that need to be given in the hospital.
Fresh frozen plasma: This is a blood product that can help break down bradykinin. But it’s not always used because it can make swelling worse before it gets better.
In some cases, it may not be clear whether angioedema is caused by ACE inhibitors. The symptoms can also look a lot like an allergic reaction. In these cases, healthcare professionals may try medications that help other types of angioedema, such as:
Because angioedema caused by ACE inhibitors isn’t an allergic reaction, these therapies are unlikely to help. But they won’t make ACE inhibitor-related angioedema worse.
In severe cases, the treatment priority is to help with breathing. Angioedema can be so severe that it blocks your airway. In these rare events, medical professionals may need to insert a breathing tube to keep you airway open.
How do you stop ACE inhibitors if you develop angioedema?
If you develop angioedema from ACE inhibitors, you’ll no longer be able to safely take your medication. Your healthcare team will start you on a different medication to treat high blood pressure. It’s important not to stop your medication on your own without a new medication to take its place. Stopping your medication without a replacement can lead to dangerous increases in your blood pressure.
When should you go to the ER for angioedema from ACE inhibitors?
Any amount of swelling in your face, neck, or mouth can be alarming. If your symptoms are mild, call your primary care provider to figure out the next steps. But more severe cases of angioedema are a medical emergency.
If you’re having any of the following symptoms, don’t wait to speak to your healthcare team. Call 911 or go to the nearest emergency room if you notice:
Rapid worsening of your swelling
Swelling of your tongue or throat
Difficulty breathing or catching your breath
Noisy breathing, especially when you breathe in (stridor)
A change in your voice or hoarseness
Frequently asked questions
Most people will fully recover from angioedema within 1 to 3 days after stopping an angiotensin-converting enzyme (ACE) inhibitor. For some people, episodes of angioedema may continue for several months after they stop their medication. But this is less common.
Yes, losartan can cause angioedema. Losartan belongs to a group of medications called angiotensin receptor blockers (ARBs). ARBs are related to ACE inhibitors. Angioedema from ARBs is much less common than angioedema from ACE inhibitors. But it can still happen.
There’s nothing you can do at home to reduce angioedema from ACE inhibitors. Stopping your medication and giving your body time to recover are the main steps. Severe symptoms may require treatment that’s only available in a hospital. This is why it’s important to seek emergency care for severe symptoms.
Most people will fully recover from angioedema within 1 to 3 days after stopping an angiotensin-converting enzyme (ACE) inhibitor. For some people, episodes of angioedema may continue for several months after they stop their medication. But this is less common.
Yes, losartan can cause angioedema. Losartan belongs to a group of medications called angiotensin receptor blockers (ARBs). ARBs are related to ACE inhibitors. Angioedema from ARBs is much less common than angioedema from ACE inhibitors. But it can still happen.
There’s nothing you can do at home to reduce angioedema from ACE inhibitors. Stopping your medication and giving your body time to recover are the main steps. Severe symptoms may require treatment that’s only available in a hospital. This is why it’s important to seek emergency care for severe symptoms.
The bottom line
Angiotensin-converting enzyme (ACE) inhibitors are a common prescription medication for high blood pressure. But anyone who takes these medications should be aware of the potential for angioedema. This is a relatively rare side effect, but it can be life-threatening.
Familiarize yourself with the warning signs so you know if it happens to you or someone you know. And if you develop any symptoms of angioedema, don’t take your next dose of your ACE inhibitor. Then, see a healthcare professional or go to the emergency room for prompt medical evaluation.
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References
Asad, H., et al. (2019). Incidence of angiotensin-converting enzyme-associated angioedema among African Americans compared to other races. CHEST.
Banerji, A., et al. (2017). Epidemiology of ACE inhibitor angioedema utilizing a large electronic health record. Journal of Allergy and Clinical Immunology: In Practice.
Brown, T., et al. (2017). Angiotensin-converting enzyme inhibitor–induced angioedema: A review of the literature. The Journal of Clinical Hypertension.
Goosenberg, E., et al. (2025). Ascites. StatPearls.
Khawar, H., et al. (2025). Fresh frozen plasma (FFP). StatPearls.
Kostis, W. J., et al. (2018). ACE inhibitor-induced angioedema: A review. Current Hypertension Reports.
Swanson, T. J., et al. (2023). Acquired angioedema. StatPearls.
Tou, L. C., et al. (2026). Losartan-induced angioedema: A case report and review of literature. Journal of Community Hospital Internal Medicine Perspectives.
