The dehydration strain on the heart

Some blood pressure medications can change the blood’s level of hydration, writes Dr Monish Raut

Heart health and fluid balance are interconnected. In actuality, both dehydration and several medications can alter blood pressure. Dehydration causes the heart to work harder to pump blood throughout the body, but dehydration can also result from using blood pressure medications.

Water makes up the majority of an adult’s body, and biological fluids have a big impact on cardiovascular health. Dehydration occurs when a person drinks less fluid than they lose. Chronic dehydration is a leading cause of hospital admissions and makes many medical diseases more challenging to cure. High blood pressure, often known as hypertension, occurs when the blood’s continual pressure on the blood vessel walls becomes too great. In India, over 33% of urban population and 25% of rural persons suffer from hypertension.

Only 25% of Indians in rural areas and 42% of Indians in cities are aware that they have high blood pressure. Only 25% of Indians in rural areas and 38% in urban areas receive treatment for hypertension. One-tenth of hypertensive rural Indians and one-fifth of them in urban areas manage their blood pressure. India’s summers can be especially oppressive because of the intense heat, high humidity, and dehydration. Dehydration can be brought on by a number of medical conditions.

What happens when you don’t drink enough water?

The body’s water is distributed between two compartments: intracellular water (ICW) and extracellular water (ECW). The electrolyte concentration of the water in a person’s body determines how fluids are transferred between the two compartments.

The body produces more of the chemical vasopressin, sometimes referred to as the antidiuretic hormone (ADH), when it is dehydrated. As a result, the kidneys store water, which aids in preventing further water loss through urination. But while raising systemic vascular resistance and blood vessel constriction, vasopressin also causes blood pressure to rise. Dehydration also increases the retention of sodium in the blood. Blood thickens as a result and circulates more laboriously throughout the body. Hypertension and hydration parameters were shown to be significantly correlated in a 2022 study. In people with hypertension, more salt intake or adjusting for chronic dehydration might result in high ECW. Although doctors are still unsure of the precise mechanism, dehydration and elevated BP are associated. On the other side, extreme dehydration may lead to decreased blood volume, which could cause hypovolemic shock and lower blood pressure.

Can prescription drugs cause dehydration in the body?

Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are frequently prescribed by physicians to individuals with hypertension. One negative side effect of these drugs could be dehydration. The most common symptoms of dehydration include weariness, thirsty lips and skin, dry skin, black faeces, headaches and a decrease in urine production, lightheadedness, muscle discomfort, stumbling (syncope), palpitations, and orthostatic hypotension. Typically, hypertension appears gradually, with no earlier signs or symptoms.

The following indications and symptoms, however, may occur in people with extremely high blood pressure (180/120 mm Hg or above) — headache, chest discomfort, breathing issues, nausea and dizziness, dread and perplexity, visual alterations, such as fuzzy vision and wooziness.

How to deal with hypertension and dehydration?

To rehydrate, doctors may encourage their patients to consume water. This does not raise blood pressure in younger people with good kidneys.

When a person is standing, sitting, or lying down, they can measure their blood pressure and heart rate, which are referred to as “orthostatic vital signs” by medical professionals.

This is done to determine whether dehydration requires intravenous (IV) or oral fluid replacement right away.

(The author is an academician.)