Can Dehydration Cause Heart Palpitations and Racing Heart Rate?

Colleen Doherty, MD

Medically reviewed by Jeffrey S. Lander, MDMedically reviewed by Jeffrey S. Lander, MD

Heart palpitations are an unpleasant awareness of the heart beating, often described as a "racing" or "flopping" feeling in the chest. While common and not usually dangerous, heart palpitations have numerous different causes, one of them being dehydration.

Dehydration is when a person loses more water than they take in. They also lose electrolytes, which are minerals that play a vital role in muscle contractions and preserving a proper fluid balance within the body.

<p>Inside Creative House / Getty Images</p>

Inside Creative House / Getty Images

Heart Palpitations and Dehydration: What’s the Link?

Water is the most integral component of the human body, comprising an estimated 55% to 60% of adult body weight.

When the body loses too much water, the volume of blood traveling throughout the body decreases, and blood pressure lowers.

When blood pressure lowers, a person's heart beats faster to ensure oxygen-rich blood reaches vital organs like the brain and kidneys. This increase in heart rate can be perceived as heart palpitations.

Electrolyte imbalances from dehydration can also trigger heart palpitations. Electrolytes in the bloodstream, like sodium and potassium, are charged minerals that serve many functions, including regulating muscle contractions (tightening and release of a muscle) and maintaining a delicate water balance.

If a person is dehydrated, electrolytes move in and out of cells to maintain normal fluid levels within the body. This movement can disrupt the balance of electrolytes and cause heart palpitations.



Review

Dehydration can cause heart palpitations due to the following:

  • A decline in blood volume that makes the heart beat faster

  • An imbalance of electrolytes as they try to preserve normal fluid levels



What’s Happening With Heart Palpitations?

Heart palpitations are uncomfortable sensations caused by the heart beating. The heart may feel like it's beating rapidly, slowly, or irregularly. Palpitations may come on suddenly or gradually, lasting from seconds to hours or even days.

Terms often used to describe them include:

  • Pounding

  • Skipping

  • Racing

  • Fluttering

  • Flip-flopping

While common and usually harmless, heart palpitations can sometimes signal an underlying disease that requires treatment or a dangerous abnormal heart rhythm (arrhythmia).

Getting heart palpitations evaluated by a healthcare provider is essential to determining the underlying cause.

How to Slow Heart Palpitations and Rehydrate

A healthcare provider needs to confirm that heart palpitations are stemming from dehydration.

Once that affirmation is made, mild to moderate dehydration can often be treated at home by drinking commercially available oral rehydration solutions.

Most of these solutions come in individual powder-filled packets that can be dissolved in 1 liter (L) of water (about a quart). Unlike sports drinks (Gatorade), these solutions contain the correct amount and balance of electrolytes and water necessary to rehydrate the body.

Severe cases of dehydration require intravenous (IV, meaning through the vein) fluids and monitoring in an urgent care, emergency room, or hospital setting.

Individuals who are vulnerable to the effects of dehydration, such as babies, young children, and older adults. or those with underlying kidney disease also require care at a medical facility.

In addition to cases of severe dehydration, oral rehydration solutions are contraindicated in people who:

  • Cannot keep oral rehydration solutions in their stomachs due to profuse vomiting

  • Have an ileus (slowed or stopped intestinal motility)

  • Refuse or cannot drink liquid, such as a person with severe dementia or dysphagia (trouble swallowing)

To properly correct dehydration, a free water deficit needs to be calculated by a healthcare provider. Once this is calculated, the type of fluid used and how fast the fluid is repleted can be determined.

After rehydration, drinking fluids that contain no sodium or less sodium, such as water, and eating can begin.



Seek Emergency Care

Dehydration can be severe and, in extreme cases, potentially fatal. Call 911 or go to your nearest emergency room if you (or a loved one) are:

  • Experiencing confusion

  • Feeling light-headed or have fainted

  • Have a rapid breathing or heart rate

  • Not urinating



When Heart Palpitations Are Not Related to Dehydration

Besides dehydration, there are numerous other potential causes of heart palpitations.

Heart-Related Causes

Arrhythmias are common causes of palpitations.



What Happens During a Normal Heartbeat?

During a normal heartbeat, an electrical impulse is generated within the sinoatrial (SA) node at the top of the heart, spreading down to the atrioventricular (AV) node within the heart's center.

The AV node then transmits the impulse to the ventricles (lower part of the heart), triggering them to contract and pump blood.



Disturbances along any of the above heart's electrical pathways can create an arrhythmia, which are classified as the following:

The above arrhythmias may be due to underlying structural heart conditions like damage from a prior heart attack or cardiomyopathy (enlarged or thickened heart muscle).

They can also manifest from underlying problems with the heart's electrical system, such as long QT syndrome or Wolff-Parkinson-White syndrome.

Other possible heart-related causes of palpitations include:

Non-Heart-Related Causes

Heart palpitations can also develop from several non-heart-related causes, such as:

  • Anemia (low numbers of healthy red blood cells)

  • Anxiety and stress

  • Dysautonomia (autonomic nervous system dysfunction)

  • Exercise

  • Fever

  • Hyperthyroidism (overactive thyroid gland)

  • Medication side effects

  • Panic attacks

  • Pregnancy

  • Substance use (e.g., caffeine, alcohol, cocaine, nicotine)

Seeing a Provider to Be Sure

Healthcare providers consider a person's symptoms and findings from a physical exam and various diagnostic tests to diagnose the cause of palpitations.

Medical History

During a person's appointment, a provider will inquire about the intensity and duration of the palpitations and whether other symptoms are present, such as chest pain, trouble breathing, or fainting.

They will also ask about a family history of heart problems, medications, caffeine/alcohol/recreational drug use, and the presence of other health conditions like anxiety disorders or anemia.

If dehydration is the cause of palpitations, additional symptoms like the following may be present:

  • Dark-colored urine and urinating less than usual

  • Decreased sweating

  • Excess thirst

  • Headache

  • Light-headedness and confusion (severe cases)

  • Muscle cramps

  • Tiredness

A history of the following also supports a possible diagnosis of dehydration:

  • Heavy sweating, like due to intense exercise or in hot weather

  • High fever

  • Poor water intake

  • Severe diarrhea or vomiting

  • Taking a medication that increases urination (peeing) like diuretics ("water pills")

Physical Exam

During the physical exam, vital signs (temperature, heart rate, blood pressure, breathing rate) will be taken, and the provider will listen to the heart with a stethoscope.

Signs on physical exam of dehydration can include:

  • Dry lips and tongue

  • Low blood pressure

  • Fast breathing rate

  • Fast heart rate

  • Reduced skin turgor (elasticity)



Dehydration in Babies and Kids

Symptoms and signs of dehydration in babies and kids include:

  • Increased thirst

  • Urinating less than usual (e.g., less than six wet diapers per day for babies)

  • Few tears

  • A sunken soft spot on a baby's head

  • Sunken eyes

  • Drowsiness or rapid breathing (severe, requiring emergency care)



Diagnostic Tests

Diagnostic tests can help pinpoint the cause of palpitations.

An electrocardiogram (ECG or EKG) measures the heart's electrical activity and is a crucial first test for evaluating palpitations. It can help detect arrhythmias like atrial fibrillation and provide clues about heart disease.

If the ECG is normal, but an arrhythmia is still suspected, a type of ambulatory ECG monitoring called a Holter monitor study is performed.



What Is a Holter Monitor?

A Holter monitor is a device worn on the body for 24 to 48 hours. It records the heart's electrical activity as the wearer goes about their day.



Other tests that might be ordered when evaluating palpitations include:



Blood Test Results

Electrolyte abnormalities and an elevated blood urea nitrogen (BUN) and creatinine ratio on a BMP support a possible diagnosis of dehydration.



Summary

Heart palpitations are an awareness of one's heartbeat, often described as "racing" or "flopping." Many possible causes of heart palpitations exist, ranging from abnormal heart rhythms to non-heart-related conditions or scenarios like anemia, caffeine use, anxiety, and dehydration.

Dehydration occurs when you lose more water than you take in. In addition to water loss, there is an imbalance of electrolytes, which are minerals that help the body maintain a tight fluid balance.

When a person is dehydrated, the reduced blood volume makes the heart beat faster, which can cause palpitations. An imbalance in electrolytes from fluid shifts also contributes to the manifestation of heart palpitations.

Mild to moderate dehydration is often treated at home by drinking oral rehydration solutions at a specific rate based on weight over four hours. In severe cases of dehydration or cases in which medical monitoring is required (e.g., kidney disease or inability to drink liquids), hospitalization with IV fluids is necessary.

Read the original article on Verywell Health.

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