Multiple Sclerosis (MS) is a chronic disease where the immune system attacks the central nervous system (CNS). This damages the protective myelin sheath surrounding nerve fibers, disrupting communication pathways. People with MS frequently report sensory disturbances, including pronounced thermal discomfort. This sensitivity often involves a persistent or sudden sensation of being cold, despite the ambient environment.
Multiple Sclerosis and Temperature Sensitivity
The experience of feeling cold is a recognized symptom of MS, categorized as thermal dysregulation. This sensation is often not due to a low core body temperature, but rather a misfiring of the sensory system. The feeling of cold is frequently a form of dysesthesia, an abnormal sensation resulting from nerve damage.
This sensory issue can manifest as persistent coldness in the extremities or a generalized deep chill that resists normal warming methods. The cold sensation can also be part of a painful, squeezing feeling around the torso or limbs, sometimes called the “MS hug.” Damaged nerves become hypersensitive, leading to an exaggerated perception of coldness.
The sensitivity can be triggered by minor environmental changes, such as a light breeze, air conditioning, or getting wet. Cold temperatures can temporarily worsen existing neurological symptoms like spasticity and numbness. This temporary worsening is known as a pseudo-exacerbation, which resolves once the body’s temperature returns to its usual range.
The Central Nervous System Connection
The mechanism behind this cold sensation lies in the damage MS inflicts upon the central nervous system (CNS). MS lesions, which are areas of demyelination and scarring, disrupt the neural pathways that transmit temperature data to the brain. These pathways are responsible for conveying signals about hot and cold from the body to the processing centers.
When the myelin sheath is stripped away, the exposed nerve fibers become electrically unstable and prone to sending erratic signals. A nerve fiber that should signal a neutral temperature might spontaneously fire, sending a strong “cold” message instead. The brain interprets this signal, received through damaged wiring, as a genuine, intense chill.
The hypothalamus functions as the body’s primary thermostat, monitoring core temperature and initiating responses like shivering or sweating. Lesions near the hypothalamus can directly impair this thermoregulatory function. Damage prevents the brain from effectively coordinating autonomic responses, such as vasoconstriction or shivering, which conserve heat. This dysfunction results in difficulty regulating skin temperature and a feeling of being constantly cold.
Managing the Sensation of Cold
Coping with MS-related cold sensitivity involves maintaining a stable thermal environment. Layering clothing is an effective method, allowing for fine-tuning of warmth and preventing sudden temperature shifts that can trigger symptoms. Thermal base layers, fleece, and wool provide substantial warmth without excessive bulk.
Maintaining a consistent indoor temperature is beneficial, as avoiding extreme fluctuations reduces shock to the nervous system. Localized heating sources, like heating pads or electric blankets, can target particularly cold areas. Caution is necessary when using these tools, as altered skin sensation increases the risk of burns.
Behavioral adjustments include drinking warm beverages like tea or broth to warm the body internally. Regular, gentle movement can improve circulation and combat the muscle stiffness, or spasticity, that cold exposure exacerbates. These techniques aim to create a stable environment, minimizing the misinterpretation of temperature signals.