What should you know about cold night sweats?

Sweating while asleep can leave your skin and clothes damp; feeling cold afterwards may simply reflect evaporation or a cool bedroom. Fever, an infection, alcohol, some medicines, low blood sugar, anxiety and hormonal changes can also cause sweating. Menopause may bring night sweats, while an overactive thyroid can cause heat intolerance, a fast heartbeat and tremor. Less common illnesses, including Brucellosis, Glandular Fever, HIV Infection, Hodgkin Lymphoma, Lymphoma or Chronic Myeloid Leukaemia, can present with night sweats, but a sweat episode alone does not identify any of them.

Note when the episodes happen, how wet the bedding becomes, and whether you have fever, cough, pain, diarrhoea, tiredness or enlarged glands. Keep the room comfortably cool, use breathable sleepwear and replace damp clothing. Check whether a new medicine or dose change came before the symptom, but do not stop prescribed treatment without advice. Arrange a routine appointment if sweating keeps returning, disrupts sleep or comes with other symptoms. A clinician may ask about travel, infections, medicines, menstrual changes and thyroid symptoms before deciding whether examination or tests are needed.

Seek urgent help for cold sweating with chest pain, severe breathlessness, fainting, confusion, a very severe headache or signs of shock such as clammy skin and marked weakness. Get prompt medical advice for persistent fever, unexplained weight loss, a new painless swollen gland, a lasting cough or reduced immunity. These warning features guide urgency; they do not prove that a particular condition is present.

Could my medicines, thyroid symptoms or hormonal changes explain the sweating? What details should I record before an appointment? Which accompanying symptoms would make you want to examine me sooner?