Sweating is a natural and important bodily function that helps regulate body temperature, keeping us cool. For individuals with diabetes, however, sweating can manifest in unusual ways, presenting as either excessive perspiration or a reduced ability to sweat. These patterns signal the body’s systems are affected by the condition. Understanding these changes can help individuals manage their diabetes more effectively.
Nerve Damage and Sweating
Long-term high blood sugar can lead to nerve damage, a common diabetic complication known as neuropathy. Affected nerves can disrupt the body’s ability to maintain temperature and produce correct sweat. Specifically, the autonomic nervous system, controlling involuntary functions like sweating, can be impacted.
Autonomic neuropathy can cause sweat glands to receive incorrect signals, leading to either excessive sweating (hyperhidrosis) or insufficient sweating (anhidrosis). Hyperhidrosis often occurs in the upper body (face, scalp, neck, chest), even at night or in cool environments without apparent reason. In contrast, anhidrosis, a reduced ability to sweat, typically affects the lower extremities, making body cooling difficult in hot conditions, potentially leading to heat intolerance.
Gustatory sweating, a specific autonomic neuropathy manifestation, causes sweating on the face, scalp, and neck shortly after eating. While many experience facial sweating with hot or spicy foods, those with diabetic neuropathy may experience it more, even when thinking about food. This sweating results from nerve damage affecting salivary and sweat glands.
Low Blood Sugar
Sweating is a common and often early symptom of hypoglycemia, a condition where blood sugar levels drop too low, typically below 70 milligrams per deciliter (mg/dL). When blood sugar falls, the body initiates a “fight or flight” response, releasing stress hormones like adrenaline and noradrenaline from the adrenal glands. Adrenaline triggers physiological changes to raise blood sugar, including stimulating the liver to release stored glucose. This hormone also activates sweat glands, leading to noticeable perspiration. This sweating is often accompanied by other symptoms like shakiness, a rapid heartbeat, anxiety, and dizziness.
This acute sweating response serves as a warning sign for individuals with diabetes that their blood sugar is critically low. Night sweats, excessive perspiration during sleep, are a result of nocturnal hypoglycemia. This occurs when blood sugar drops overnight, leading to stress hormone release and soaked bedding.
Medication Effects
Certain medications prescribed to manage diabetes can also contribute to sweating as a side effect. Some diabetes medications, such as insulin and sulfonylureas (e.g., glipizide), are designed to lower blood sugar levels. These medications can sometimes lower blood glucose too much, causing hypoglycemia and its associated sweating. Therefore, while the medication itself does not directly cause sweating, its effect on blood sugar can induce perspiration as a secondary symptom.
Other medications, not necessarily for diabetes, can also have sweating as a side effect, including some antidepressants, pain relievers, and hormonal medications. If unusual sweating occurs, especially when starting new medications, it is advisable to discuss it with a healthcare provider.