Can Dehydration Cause Shortness of Breath? Dr Badran Answers

By Dr Magdy Badran

Dehydration affects nearly every system in the body, and the lungs are no exception. When dehydration occurs, the mucus in the lungs and sinuses becomes thicker and stickier, making breathing more challenging. Likewise, dehydration dries out airway passages and increases the risk of respiratory illness and allergies. These situations can lead to shortness of breath. This effect is easier to see in individuals with chronic respiratory medical problems.

The two main mechanisms that would lead to breathing difficulties when dehydrated would be hypotension and lactic acidosis.

Dehydration and Hypotension

Hypotension (low blood pressure) is when the blood pressure reading is lower than 90/60 mm Hg. Blood volume is the amount of fluid that’s circulating in your blood vessels. Maintaining a normal blood volume is necessary for blood to be able to adequately reach all of the tissues of your body. In dehydration, the blood volume can decrease, leading to a drop in blood pressure. Common symptoms include chest pain and difficulty breathing.

Dehydration and Lactic Acidosis

Metabolic acidosis develops when the body has too much acidic ions in the blood. It occurs when the kidneys cannot remove enough acid from the body. Metabolic acidosis can be caused by severe dehydration following vomiting and diarrhea.

Basically, there’s an imbalance of acids and bases in your blood. A person who has a blood pH below 7.35 is considered to be in acidosis. Excess lactic acid building up in the lungs can cause shortness of breath and other symptoms like rapid breathing or muscle cramps.

Smoking and Dehydration

Hot air and cigarette smoke cause airway dehydration. The first mechanism by which cigarette smoke contributes to airway surface dehydration is diuresis. Nicotine acts as a diuretic that increases urine production and excretion – leading to dehydration, especially without regular or increased water intake while smoking.

A second mechanism by which cigarette smoke can contribute to airway surface dehydration, is the mucin hypersecretion. This mucus collects in the airways, making breathing more difficult.

Dehydration Affects Oxygen Levels

Low blood volume shock (hypovolemic shock) is one of the most serious, and sometimes life-threatening, complications of dehydration. It occurs when low blood volume causes a drop in blood pressure and a drop in the amount of oxygen in the body.

Dehydration and Asthma

Hydration certainly plays an important role in the ability to thin and clear secretions. Dehydration produces histamines. If histamine is being produced, allergies are triggered, and therefore asthma is aggravated. A good asthma and general health management plan should include drinking plenty of water.

Dehydration can worsen exercise-induced asthma. Asthmatics are more sensitive to dehydration than non-asthmatics. Additionally, dehydration can often be associated with a side effect of asthma and its medications.

Dehydration and Respiratory Rate

Dehydration and respiratory rate are related. Dehydration has been shown to increase the respiratory rate in several species. This is due to the role of the autonomic nervous system (ANS) in controlling the rate of breathing in response to various physiological conditions. In general, the ANS is responsible for regulating the rate and depth of breathing in response to changes in the environment. When the body loses fluids, the ANS responds by increasing the rate and depth of breathing to compensate for the loss of fluid.

When people become dehydrated, their body functions change. Not being able to sweat can cause a person’s body temperature to rise, which can result in hyperthermia. As a result, their sweat glands slow or stop producing sweat, causing the body to lose water or electrolytes. This can lead to a host of health problems, which is why it’s so important to stay hydrated.

Getting dehydrated can have many effects on the body, one of which is an increased respiration rate. This occurs when the body is losing water, and therefore loses its ability to function properly. Because of this, the body must work harder in order to maintain the same functions. This can cause a number of problems, including fatigue, headaches, dizziness, and shortness of breath.

Risk Factors

Anyone can become dehydrated, but certain people are at greater risk as infants and children, older adults, people with chronic illnesses, and people who work or exercise outside.

Some medications have side effects, like increased urination or profuse sweating. These medications put you at risk for dehydration, especially if you don't know about the specific side effects of the drug.

Tips For Preventing Dehydration

Remember to drink plenty of water throughout the day. Milk has been shown to help with rehydration because of its sodium, carbohydrate, and protein content.

Try to drink water regularly throughout the day. Drink a glass of water when you wake up. After spending eight hours in bed not drinking anything, it’s easy to wake up in a dehydrated state. Ignore the popular rule to drink 8 glasses of water a day (It’s not enough).

Assess the inside of your mouth for dehydration symptoms. Be sure to increase your fluid intake on hot or humid days, or before or after exercise. Drink more water when you’re sick.

Carry a water bottle with you so you always have something to drink. If you work outside, be sure to take frequent breaks in a cool or shady place.

It’s wise to avoid carbonated or sugary drinks, caffeine, and alcohol as all of these can dehydrate you, especially when it’s hot outside.

Think beyond plain water to help stave off dehydration. You can help prevent dehydration by filling your diet with fruits and vegetables that have a high-water content. Fruits like cantaloupe, strawberries, and watermelon are 90 to 99 percent water, while apples, grapes, oranges, and pineapple are between 80 and 89 percent water.