Cold sweats, medically known as diaphoresis, represent a physical reaction where a person sweats profusely despite not being hot or engaged in physical exertion. Unlike normal sweating, which cools the body through evaporation, cold sweats are a symptom of the body reacting to internal distress or a perceived threat. This clammy, often cool, perspiration is usually a manifestation of the sympathetic nervous system activating the fight-or-flight response. Cold sweats are not a diagnosis themselves but rather a general warning sign of physiological stress.
Stress and Acute Nervous System Reactions
The sympathetic nervous system is often the direct trigger for non-thermoregulatory sweating. When extreme emotional states like intense fear, panic attacks, or overwhelming anxiety occur, the brain signals the release of catecholamines, primarily adrenaline. This surge of hormones prepares the body for immediate action by elevating the heart rate and blood pressure. This activation causes peripheral vasoconstriction, where blood vessels near the skin constrict. Redirecting blood flow to the core and major muscles causes the skin to become cool and pale, even as stress hormones stimulate the sweat glands, resulting in the characteristic cold, clammy feeling.
Sudden Circulatory and Systemic Distress
Cold sweats can signal a severe disruption in the body’s circulatory system, indicating a medical emergency where the body struggles to maintain adequate blood flow to vital organs. Various forms of shock, such as hypovolemic shock or septic shock, cause a rapid drop in blood pressure. The body compensates for this systemic failure by shunting blood away from the extremities and skin to prioritize the brain and heart. This mechanism results in the skin becoming cool, pale, and clammy as the body conserves volume centrally. Acute cardiac events, like a heart attack, also frequently manifest with cold sweats because the heart’s compromised pumping ability stresses the system, triggering the widespread sympathetic response.
Issues with Blood Sugar and Hormonal Regulation
Metabolic imbalances, particularly low blood sugar (hypoglycemia), are a common cause of cold sweats, as the body interprets insufficient glucose as a crisis. When glucose levels drop too low, the adrenal glands release adrenaline and cortisol. These hormones mobilize stored energy to raise blood sugar back to a safe range. The rush of adrenaline directly stimulates the sweat glands, causing clammy perspiration, which is often an early warning sign for individuals with diabetes. Hormonal shifts unrelated to acute stress, such as those during menopause, can also trigger profuse sweating that leaves the skin feeling cold as the moisture evaporates.
Infections and Substance Withdrawal
Infections can cause cold sweats through mechanisms related to temperature regulation. When a fever breaks (defervescence), the body rapidly attempts to shed excess heat, often resulting in heavy, drenching cold sweats as the core temperature returns to normal. In severe systemic infections like sepsis, cold sweats are also part of the body’s response to circulatory failure. Substance withdrawal, particularly from alcohol or opioids, triggers a hyperactive state in the autonomic nervous system. The cessation of the substance leads to a rebound effect where the nervous system is overstimulated, causing tremors, anxiety, and periods of profuse, cold sweating.