Dehydration can cause more than thirst: Expert explains how it can affect the heart

Dehydration impacts more than just thirst, according to Dr. Brodie Marthaler, a cardiologist at Mayo Clinic Health System, it can also put additional strain on the heart and cardiovascular system. The heart functions like a pump, relying on sufficient blood flow to operate effectively. When dehydrated, the blood volume in the body decreases, reducing the amount of blood returning to the heart with each beat. Consequently, the heart must work harder to maintain proper circulation throughout the body.

In response to dehydration, the body employs several mechanisms to maintain blood pressure. Blood vessels constrict, and the heart rate increases to ensure adequate blood flow. However, if dehydration becomes severe, these compensatory responses may falter. Organs such as the brain, kidneys, liver, and digestive system could receive insufficient blood supply, leading to impaired functioning.

Symptoms of severe dehydration can include dizziness, palpitations, chest discomfort, fainting, or heatstroke, which are medical emergencies requiring immediate attention from a healthcare professional. While dehydration can affect anyone, certain individuals are at higher risk, including those with heart failure or other heart conditions.

These patients may have less reserve to cope with the added stress of dehydration, and many are on medications that either remove fluid from the body, lower blood pressure, or slow the heart rate, limiting the body's capacity to counteract dehydration.

There is no universal guideline for water intake. Generally, thirst is a reliable indicator of hydration needs. However, for those engaging in prolonged outdoor activities in hot weather or intense exercise, increasing fluid intake beforehand is advisable. Dehydration can be challenging to detect, so other signs to watch for include a dry mouth, dry skin, dark or foamy urine, or a burning sensation during urination.

Monitoring hydration can be as simple as observing the color of urine. Pale or clear urine typically indicates adequate hydration, while darker urine may signal the need for more fluids. Water is the ideal first choice for staying hydrated; however, in cases of severe dehydration, water alone may not suffice. Electrolytes such as sodium, potassium, and magnesium are also crucial for proper bodily functions.

Drinking water alongside a salty snack can help replenish both fluids and electrolytes. During prolonged exercise or endurance activities, consuming sports drinks containing electrolytes can be particularly beneficial.

Alcohol and highly caffeinated beverages can contribute to dehydration by altering the brain and kidney regulation of fluids and increasing fluid loss. Opting for water or electrolyte-rich drinks over sugary sodas is recommended when attempting to rehydrate. To prevent dehydration, make a habit of drinking fluids regularly throughout the day, consuming smaller amounts rather than large quantities at once.

If spending time outdoors in hot or humid conditions, monitor your physical state and adjust activities accordingly. Recognizing personal risk factors, such as age, heart disease, or certain medications, can help prioritize hydration efforts. By staying vigilant and attentive to hydration needs, individuals can protect their heart health and overall well-being.