Lisinopril, one of the most widely prescribed blood pressure medications, causes side effects in a meaningful number of people. The most common are a persistent dry cough, dizziness, and headache. Most side effects are mild and manageable, but a few rare reactions require immediate attention.
The Most Common Side Effects
In clinical trials, the side effects that showed up noticeably more often in people taking lisinopril compared to a placebo were headache (3.8% more frequent), dizziness (3.5% more frequent), and cough (2.5% more frequent). These numbers represent the excess risk from the drug itself, not from the underlying condition being treated.
Dizziness tends to be more pronounced at higher doses. In a large heart failure trial comparing high and low doses, 19% of patients on the higher dose reported dizziness compared to 12% on the lower dose. This makes sense: lisinopril lowers blood pressure, and a bigger drop can leave you lightheaded, especially when standing up quickly. Fatigue and general weakness also show up in at least 1% of patients in clinical trials, though exact rates vary.
These common side effects often improve after the first few weeks as your body adjusts. Staying hydrated and standing up slowly can help with the dizziness in the meantime.
Why Lisinopril Causes a Dry Cough
The cough is the side effect most people find annoying enough to stop the medication. It’s typically dry, persistent, and tickly, often worse at night. It can start within the first few weeks or develop months into treatment.
The cough happens because of how the drug works. Lisinopril blocks an enzyme that normally breaks down a compound called bradykinin. With that enzyme blocked, bradykinin builds up in the airways and irritates the nerve endings there, triggering the cough reflex. This isn’t a sign of illness or lung damage. It’s a predictable chemical consequence of the drug’s mechanism.
Real-world rates of the cough tend to be lower than what clinical trials report, but it remains common enough that switching to a different class of blood pressure medication (typically an ARB, which works on the same system without the bradykinin buildup) is a standard next step if the cough becomes intolerable.
Effects on Potassium Levels
Lisinopril can cause your body to hold onto more potassium than usual, a condition called hyperkalemia. In a large study of nearly 53,000 patients starting this class of medication, about 5.6% developed mildly elevated potassium levels and 1.7% reached levels considered more clinically significant.
For most people, this shift is small and harmless. But potassium that climbs too high can cause muscle weakness, numbness, and in severe cases, dangerous heart rhythm changes. Your risk is higher if you have kidney problems, diabetes, or if you take other things that raise potassium: potassium supplements, potassium-containing salt substitutes, certain “water pills” (potassium-sparing diuretics), or regular use of NSAIDs like ibuprofen or naproxen.
This is why doctors typically check your blood work before starting lisinopril and again within the first one to four weeks. If you’re in a higher-risk group, expect more frequent monitoring early on.
Effects on Kidney Function
Lisinopril can cause a small, temporary bump in creatinine, a marker of kidney function. A modest increase is expected and generally not a problem. The threshold that signals trouble is a rise of 30% or more after starting the medication. At that point, your doctor will likely adjust or stop the drug.
Paradoxically, lisinopril is often prescribed specifically to protect the kidneys in people with diabetes or chronic kidney disease. The short-term dip in kidney filtration is usually a trade-off for long-term preservation of kidney function. But this balance depends on your starting kidney health, which is why monitoring matters.
Angioedema: Rare but Serious
The most important rare side effect is angioedema, a sudden swelling of the face, lips, tongue, or throat. It affects roughly 0.5% of people who take lisinopril or similar medications. In a study of over 145,000 patients on this drug class, 716 developed angioedema.
Certain groups face higher risk. Women are about 1.4 times more likely to develop it than men. Black patients are nearly three times more likely than white patients. People who regularly take NSAIDs also have elevated risk. Angioedema can happen at any point during treatment, not just in the early weeks, which makes it worth knowing about even if you’ve been on the medication for a long time.
If you notice swelling in your face, lips, or tongue, or have difficulty breathing or swallowing, this requires emergency medical care. The reaction can obstruct the airway. Anyone who experiences angioedema on lisinopril should not take it (or any related ACE inhibitor) again.
Other Rare but Serious Reactions
A small number of cases involve more severe organ-level effects. Liver injury has been reported rarely with this drug class, sometimes starting as yellowing of the skin or eyes (jaundice) and potentially progressing to serious liver damage. If you develop unexplained nausea, abdominal pain, or yellowing of the skin while on lisinopril, that warrants prompt medical evaluation.
Blood cell changes are also possible but uncommon. Rare cases of significantly reduced white blood cell counts have been reported, which can leave you more vulnerable to infections. This risk is higher in people who have both kidney disease and an autoimmune condition. Symptoms to watch for include unexplained fever, sore throat, or unusual fatigue that feels different from the mild tiredness the drug can cause.
Pregnancy Risks
Lisinopril carries an FDA black box warning for use during pregnancy. Taking it during the second or third trimester has been linked to serious harm to the developing baby, including kidney failure, skull abnormalities, underdeveloped lungs, and in some cases, death. Even first-trimester exposure may increase the risk of major birth defects based on retrospective data.
If you become pregnant while taking lisinopril, stopping the medication as soon as possible is critical. If you’re planning a pregnancy, your doctor will switch you to a blood pressure medication with a safer pregnancy profile well in advance.
Drug Interactions That Increase Risk
Several common medications and supplements can amplify lisinopril’s side effects. The most important interactions to know about:
- Potassium supplements and salt substitutes: These can push potassium to dangerous levels when combined with lisinopril. Many “low-sodium” salt alternatives are potassium-based, so check labels.
- NSAIDs (ibuprofen, naproxen): Regular use can both raise potassium levels and reduce lisinopril’s blood-pressure-lowering effect. Occasional use is generally less concerning than daily use.
- Potassium-sparing diuretics: These water pills prevent potassium loss, which stacks with lisinopril’s own potassium-retaining effect.
The combination of kidney problems, diabetes, and any of the above factors creates the highest risk scenario for dangerous potassium elevation. If you take lisinopril alongside any of these, regular blood work becomes especially important.