High blood pressure is one of the most common health problems in the world. It often has no clear symptoms, but over time it can quietly damage the heart, brain, and kidneys. If left untreated, it greatly increases the risk of heart attacks, strokes, and heart failure.
Because of this, millions of people take daily medication to keep their blood pressure under control. Two of the most widely used drugs for this purpose are chlorthalidone and hydrochlorothiazide, which belong to a group of medicines called diuretics. These drugs help the body remove extra salt and water through urine, which lowers blood pressure.
A major new study led by researchers at Columbia University has compared the long-term safety of these two medications. The research followed more than 730,000 people over 17 years, making it one of the largest studies of its kind.
The results showed that both drugs work well at lowering blood pressure and preventing serious problems such as heart attacks, strokes, and heart failure. However, the study also found that chlorthalidone may cause more side effects than hydrochlorothiazide.
The most serious concern linked to chlorthalidone is low potassium levels in the blood, a condition known as hypokalemia. Potassium is a mineral that helps nerves and muscles function properly, especially the heart muscle.
When potassium levels drop too low, people may experience weakness, tiredness, muscle cramps, or abnormal heart rhythms. In severe cases, low potassium can lead to confusion, kidney problems, and a higher risk of developing type 2 diabetes.
The study found that about 6.3 percent of patients taking chlorthalidone developed hypokalemia, compared with only 1.9 percent of those taking hydrochlorothiazide. This means the risk was about three times higher with chlorthalidone.
Researchers also found that people on chlorthalidone had greater chances of other problems, including imbalances of important minerals in the body and reduced kidney function. These risks were seen even in patients taking lower doses of the drug.
These findings have led experts to question whether chlorthalidone should continue to be a first-choice treatment for high blood pressure.
Some doctors may now choose to monitor potassium levels and kidney function more closely in patients who take this medicine. Others may consider prescribing alternative drugs, especially for people who already have kidney disease or are at risk of electrolyte problems.
Despite these concerns, managing high blood pressure remains extremely important. Medication is often necessary, but healthy lifestyle choices also play a key role.
Eating a balanced diet with less salt, staying physically active, limiting alcohol, avoiding smoking, and reducing stress can all help lower blood pressure naturally. Many doctors also recommend checking blood pressure at home so patients can track their progress and detect problems early.
The study, led by Dr. George Hripcsak and published in JAMA Internal Medicine, highlights the need for personalized treatment.
Not every medication is suitable for every patient, and doctors must balance the benefits of lowering blood pressure with the risk of side effects. As scientists continue to study these drugs, future treatments may become safer and more tailored to individual needs.
This research offers valuable guidance for both doctors and patients. By understanding the risks as well as the benefits of common medications, people can make informed decisions about their health and work with their healthcare providers to choose the safest and most effective treatment plan.
If you care about blood pressure, please read studies about unhealthy habits that could increase high blood pressure risk, and people with severe high blood pressure should reduce coffee intake.
For more information about blood pressure, please see recent studies that early time-restricted eating could help improve blood pressure, and results showing plant-based foods could benefit people with high blood pressure.
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