Why do I constantly feel thirsty during sleep?

PHOTO: Why do I constantly feel thirsty during sleep?

Q. I am a 49-year-old woman. I wake up almost every other hour to drink water throughout the night.

My mouth would be completely dry, like a piece of paper. I sleep in an air-conditioned room, with the fan on, but will place a glass of water in the room to "moderate" the dryness of the air.

This has been happening for the past year. Is there a reason why I constantly feel thirsty during sleep?

A. As placing a glass of water in the air-conditioned room at night to humidify the air did not improve your mouth dryness and thirst, then it is unlikely that your symptom is caused by the environment you sleep in.

Feeling thirsty every night and having to drink frequently to relieve thirst can either signal dehydration resulting from increased water loss from the body, or reduced saliva production from the salivary glands.

If you are also experiencing frequent urination during the day or night, you should see a doctor to be investigated for possible diabetes mellitus or diabetes insipidus.

In a person with diabetes mellitus, the blood sugar level is higher than normal and there will be increased urination as the kidneys try to get rid of the excess sugar in the body.

He will therefore experience thirst as a result of water loss due to frequent urination.

There might be other accompanying symptoms related to the high blood sugar, such as weight loss, blurring of vision and fatigue.

As for someone with diabetes insipidus, there is an insufficient amount of anti-diuretic hormone (ADH) in the body.

ADH helps to balance the amount of fluids in the body. When the body lacks this hormone, the kidneys will pass out more water, resulting in increased urination. Thirst occurs as a result of the increased water loss.

In both conditions, the frequent urination can occur throughout the day and can also happen in the middle of the night (nocturia).

If you do not encounter increased or frequent urination, but have dry eyes and dry skin together with a dry mouth, you will need to consult a doctor to be investigated for possible Sjogren's syndrome.

This is a condition that occurs when the body's immune system "attacks" glands that keep the eyes, mouth, and other parts of the body moist. Some people with Sjogren's syndrome have other immune system conditions such as rheumatoid arthritis, lupus and scleroderma.

You should see a doctor so that he can evaluate your symptoms and determine the necessary tests to find out the cause of your problem.

DR ABEL SOH
Specialist in endocrinology and consultant at Raffles Diabetes & Endocrine Centre


Get a copy of Mind Your Body, The Straits Times or go to straitstimes.com for more stories.