Brief Answer:
Most common: hormones, medications, anxiety, lymphomas

Detailed Answer:
Hello and welcome,

I'll give you information as it pertains to people living in the US. In other countries there can be other causes that are more common, such as infectious diseases like malaria and TB. And of course very hot weather can do this too.

But in women in the US, the most common cause of night sweats is due to hormones. Number one would be menopause, but also hormonal therapy with estrogen. Excess thyroxine in hyperthyroidism is another hormonal cause.

Some medications can cause sweating including certain antidepressants, and blood sugar lowering medicines.

Anxiety and panic attacks can cause a person to wake up at night in a sweat.

Less common but still significant causes include cancer. In particular, lymphoma but other cancers can cause this too.

There are other causes (infections, neurological, etc), but you asked for the most common so I'll limit the list there.

I hope this information helps.

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