Brief Answer:
various causes

Detailed Answer:
Hello,

there are a lot of potential causes for this symptom. Before going on to investigate the various medical conditions, please make sure that the temperature in your room in appropriate and you don't use too many blankets.

If you can recognize this sweating as abnormal then you can consider some of the following causes:
- infections: a rise in the temperature is expected. When the temperature falls, sweating occurs. Some infections may cause profound sweating like Brucellosis or tuberculosis.
- Hematologic malignancies: when causing night sweats, they usually also cause weight loss and fatigue.
- other hematologic disorders like myelofibrosis.
- hyperthyroidism: it causes sweating all the time (not exclusively during the night)
- Obstructive sleep apnea: it may cause sweating when the patient struggles to take a breath.
- carcinoid syndrome: can also present with diarrhea, flushing, etc
- anxiety

Please keep in mind that clinically important sweating involves a lot of sweat, you have to soak the sheets! Do not consider it as a serious symptom if you just feel hot and a little sweat in your axillae.

I hope you find my comments helpful!
You can contact me again, if you'd like any clarification or further information.

Kind Regards!

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