Low blood pressure is a term used to describe less-than-average pressure inside your arteries when your heart contracts and relaxes. If you develop this condition, you can experience dizziness, fainting or more severe health problems. Low blood pressure-related dizziness during exercise has a variety of potential underlying causes.
Basics
Low blood pressure is also commonly known as hypotension. Technically, it occurs when the pressure in your arteries drops below 90 mm of mercury, or mmHg, when your heart contracts or when your arterial pressure drops below 60 mmHg when your heart relaxes. However, because of slight variations in blood pressure between different people, you can have active or resting pressure readings below normal without developing low blood pressure symptoms.
In addition to dizziness and fainting, individuals with severely low blood pressure can develop oxygen and nutrient deficiencies in their brains or other essential organs. In turn, these deficiencies can trigger the life-threatening condition called hypovolemic shock, or simply shock.
Dehydration
If you exercise without replacing the liquids you lose through sweating, you can develop varying degrees of dehydration. In turn, dehydration can trigger the onset of low blood pressure. Even mild cases of dehydration can trigger pressure-related dizziness, as well as feelings of fatigue or physical weakness.
Additional potential symptoms of dehydration include a sticky or dry feeling in your mouth, lack of tear production, little or no urine output and a sunken appearance around your eyes. If you develop severe dehydration, the bodily disruptions caused by shock can kill you within a period of minutes to hours.
Additional Underlying Causes
Low blood pressure and/or dizziness during exercise can also stem from a variety of heart-related health problems. These problems include blockages in your coronary arteries, an enlarged heart, disease in your heart valves and certain congenital heart defects. You can also develop exercise-related low blood pressure and dizziness if you have an abnormally accelerated heart rate or malfunctions in your autonomic nervous system, which normally controls your blood pressure and other involuntary functions in your body.
Prevention and Treatment
You can avoid dehydration by drinking plenty of water or sports drinks before and during your exercise routine. You can also ease mild dehydration by drinking fluids after exercise. However, you will likely need to receive treatment in a hospital if you have mild or severe dehydration.
If you become dizzy during exercise, seek medical assistance as soon as possible. After you get help from emergency personnel, your doctor can uncover the specific cause of your dizziness and provide you with proper long-term treatment.
