5 Answers

Medical professionals recommend that those who suffer from these nuisances for a prolonged period seek the advice of a medical professional as it could be a symptom of a more serious medical problem.

Night sweats. Aren't they related to stress? Everybody know stress sweat stinks..........

Assuming he took a shower before bedtime.   Night sweats the body is excreting many toxins.

As Romos  says, probably good idea to visit a doctor.  Regardless of him telling you. "I always sweat like that'.

Too much late night garlic will do it.

 I searched for some information and found a website where A LOT of people were asking the same question.  Some of the possible problems included liver function, hypoglycemia, pre-cardiac problems, pre-cancer problems, medications  (including nitroglycerin, Viagra, various antidepressants, and even acetominaphine).  Here's some of the context I got from one of the articles:

For women, the complication could very simply be related to hormonal fluctuations but, for men, the presence of night sweats may mark a more severe medical condition.

While we all, at some point, sweat in our sleep, it is the man who sweats so profusely that a change of clothes is required, who may have a concern in terms of health complications. For men who suffer from fever, cough or aches and pains, the night sweats may simply be attributed to an infection that will resolve, either through time or through use of antibiotics.

But, for those men who do not experience viral or bacterial infection, the onset of night sweats can be an indication of a far more severe complication. To determine the cause of your underlying night sweats, your healthcare professional will want to conduct a variety of diagnostic studies, including checking vital signs, running blood work and even conducting a chest x-ray as, in some cases, night sweats may be attributed to tuberculosis.

As a man, your blood work will provide an insight into such conditions as diabetes, which can lead to night sweats through the development of nocturnal hypoglycemia, and complications associated with the thyroid gland; all of which lead to complications in sleep, including sleep disorders.

In the most complex diagnosis of night sweats, even after all other testing has come relatively normal, it is possible that you may be experiencing night sweats in response to an underlying malignancy or pre-cancerous complication. Such complications, for men, may include silent neoplasm, which can be diagnosed through CT scans.

When all studies fails to show or reveal any underlying condition, as a man you may simply be experiencing a condition known as benign night sweats. These are simply night sweats of no known cause or origin and may simply be attributed to "over-bundling", also known as a poorly ventilated room or using too many pieces of clothing or blankets. While this seems to make logical sense, many men find the over-bundling is, indeed, the cause for night sweats with some finding it simply necessary to sleep in the nude.

When suffering from night sweats, it is important to seek out medical attention from your healthcare provider and request not only physical examination but also an assessment of blood work, x-ray and CT of the chest. Through this comprehensive evaluation, the cause and origin can be identified and provide for a restoration in your sleep-filled nights.

 I hope your BF heeds all this good advice and gets the problem diagnosed properly.