Cryotherapy involves exposing the body to extremely low temperatures, often ranging from -110°C to -140°C, through whole-body chambers or localized application. This brief, intense cold exposure induces a systemic physiological response, including rapid vasoconstriction followed by vasodilation upon exit. While generally well-tolerated by healthy individuals, the procedure is not universally safe and carries specific risks for people with certain health conditions. These medical conditions, known as contraindications, render the treatment unsafe or significantly increase the likelihood of adverse health events.
Health Conditions Affecting Circulation and Blood Pressure
Conditions that compromise the cardiovascular system or affect the body’s response to cold are serious absolute contraindications. A rapid drop in temperature causes immediate constriction of peripheral blood vessels, a reflex known as vasoconstriction. This response shunts blood toward the body’s core to protect vital organs, but it can dangerously elevate systemic blood pressure.
For people with severe, uncontrolled hypertension (exceeding 180/100 mmHg), cold-induced vasoconstriction can lead to a hypertensive crisis. Individuals with a history of serious cardiovascular events, such as a recent myocardial infarction, unstable angina pectorus, or stroke, are also at high risk. The increased cardiac workload and sudden changes in blood flow can potentially trigger an arrhythmia or further cardiovascular damage.
Certain blood flow disorders are also incompatible with cryotherapy due to an abnormal cold sensitivity. Raynaud’s phenomenon, for instance, is characterized by an exaggerated reduction of blood flow in the fingers and toes in response to cold or stress. Exposing the body to cryogenic temperatures can trigger a severe episode of vasospasm, potentially leading to tissue damage in the extremities.
Cold urticaria is an immune reaction where cold exposure causes the release of histamine. This leads to hives, or red, itchy welts, and in severe cases, can cause a dangerous systemic allergic reaction. Other circulatory issues like peripheral arterial occlusive disease or deep vein thrombosis (DVT) also pose risks, as the extreme cold can further restrict compromised blood vessels, potentially exacerbating the underlying condition.
Skin Integrity Issues and Local Infections
Cryotherapy is contraindicated where the skin’s protective barrier is compromised or an active infection is present. Applying extreme cold to an area with an open wound, an ulcer, or active bleeding impedes the natural healing process. Cold exposure can suppress the inflammatory response necessary for tissue repair and lead to further localized damage.
Severe skin infections, such as cellulitis or erysipelas, are absolute contraindications because cold exposure risks spreading the infection or worsening inflammation. The body’s localized immune response is temporarily altered by the extreme temperature, which can hinder the ability to contain the bacterial or viral invasion. Therefore, any active infection should be avoided until the condition is fully resolved.
A history of severe frostbite in a specific area also makes that tissue highly susceptible to future cold injury. Tissue that has previously sustained cold damage has compromised resilience and may be permanently unable to tolerate the temperature extremes of cryotherapy. The compromised microcirculation in the area increases the risk of cold burns and further tissue necrosis.
Pregnancy is a systemic contraindication for whole-body treatments. While localized cryotherapy may be used on extremities, it should be strictly avoided over the abdomen or lower back. Exposing the developing fetus to extreme cold is a precaution to eliminate potential risk, particularly during the first trimester.
Risks Related to Nerve Function and Sensation
Safe cryotherapy relies on the patient’s ability to feel and report cold or discomfort during the procedure. Conditions that impair nerve function or sensation present a clear risk because the body’s natural warning system is diminished. Peripheral neuropathy, which involves nerve damage outside the brain and spinal cord, often leads to numbness or a reduced ability to feel temperature changes, particularly in the hands and feet.
When sensation is impaired, the individual cannot accurately gauge the cold intensity, substantially increasing the risk of localized cold burns or frostbite. The absence of pain feedback means the treatment could continue too long, resulting in severe tissue injury before damage is noticed. This lack of sensory awareness removes a fundamental safety mechanism inherent in the procedure.
A separate neurological concern involves seizure disorders, including uncontrolled epilepsy. The rapid change in body temperature during cryotherapy can act as a physiological stressor or trigger. This extreme stimulus may potentially induce a seizure in susceptible individuals.