While high blood pressure is a frequent concern in individuals with diabetes, the opposite condition, low blood pressure or hypotension, can also occur. Low blood pressure becomes a concern when it produces noticeable symptoms. The presence of diabetes can contribute to the development of hypotension through various mechanisms.
Causes of Low Blood Pressure in People With Diabetes
A primary cause of hypotension in those with long-term diabetes is a condition known as diabetic autonomic neuropathy. This involves damage to the autonomic nerves, which control involuntary bodily functions like the constriction and dilation of blood vessels. When these nerves are impaired, the body’s ability to adjust blood pressure in response to changes in posture, such as standing up, is diminished.
Another factor is the side effects of certain medications. Individuals with diabetes are often treated for high blood pressure, and these antihypertensive drugs can sometimes lower blood pressure too much. Diuretics, a class of medication used to manage high blood pressure, increase urine output. This fluid loss can lead to dehydration, which reduces blood volume and causes blood pressure to fall.
Dehydration can also be a direct result of poorly managed blood sugar levels. When blood glucose is excessively high, a state known as hyperglycemia, the kidneys work to filter the excess sugar out of the blood and into the urine. This process pulls a large amount of water along with it, leading to increased urination. The resulting dehydration reduces the overall volume of blood circulating in the body, causing a drop in blood pressure.
Recognizing Hypotension Symptoms
One of the most common signs of low blood pressure in people with diabetes is orthostatic hypotension, also called postural hypotension. This manifests as a sudden feeling of dizziness, lightheadedness, or even a temporary loss of vision upon standing up from a sitting or lying position.
Beyond dizziness upon standing, other symptoms can indicate hypotension. A person might experience persistent fatigue, a general sense of weakness, or difficulty concentrating. Nausea and blurred vision are also associated with low blood pressure, as is fainting, which is medically termed syncope. These symptoms arise because the reduced blood pressure compromises the delivery of oxygen-rich blood to the brain and other organs.
Symptoms are not always constant and may appear after meals, a condition known as postprandial hypotension. This happens because the digestive process requires a significant amount of blood to be diverted to the stomach and intestines. In individuals with impaired autonomic function, the body fails to compensate for this shift in blood flow, leading to a drop in overall blood pressure and the onset of symptoms one to two hours after eating.
Associated Health Complications
Symptomatic low blood pressure increases the risk of falls and subsequent injuries. The sudden dizziness or fainting caused by orthostatic hypotension can lead to falls, which are particularly hazardous for older adults and can result in fractures. These injuries can lead to a decline in mobility and independence.
Consistently low blood pressure can compromise blood flow to vital organs like the heart, kidneys, and brain. Inadequate blood flow to the heart can exacerbate existing cardiac conditions. For the kidneys, reduced blood flow can impair their function, potentially worsening diabetic nephropathy, a form of kidney disease common in people with diabetes.
In severe cases, a drastic drop in blood pressure can lead to a life-threatening condition known as shock. During shock, the circulatory system fails to provide adequate oxygenated blood to the body’s tissues, leading to organ failure. This represents the most serious potential outcome of untreated hypotension, especially if it results from severe dehydration or an acute illness.
Management Strategies
Managing low blood pressure in the context of diabetes begins with a medical evaluation to pinpoint the underlying cause. A healthcare provider will review all current medications, such as antihypertensives or diuretics, that might contribute to the issue. Adjusting the dosage or switching to a different type of medication may be necessary to control high blood pressure without causing symptomatic lows.
Lifestyle modifications play a large part in managing hypotension. A provider may recommend increasing fluid intake to prevent dehydration. In some cases, a controlled increase in dietary salt may be advised to help the body retain more fluid, though this must be done under medical supervision. Simple behavioral changes, like rising slowly from a seated or lying position, can also help manage symptoms.
For persistent orthostatic hypotension, physical measures can provide relief. Wearing compression stockings can help prevent blood from pooling in the legs, promoting its return to the heart and maintaining more stable blood pressure upon standing. Regular monitoring of both blood pressure and blood glucose levels at home is also important to track the effectiveness of treatment strategies.