Thursday, 2 January 2025

ALWAYS THIRSTY - POLYDIPSIA - ANOTHER PROF. S.N. CHAKRABORTY MASTERCLASS

                                     

 


This is another master-class of Prof. S.N. Chakraborty which I have managed to recover from my notes of student days in King George’s Medical College in Lucknow. Prof. Chakraborty was our professor of Medicine and was an encyclopedia of knowledge. I have introduced Prof. Chakraborty to you in my previous blogs. If you have missed out on those blogs then please click:

https://www.blogger.com/blog/post/edit/8750887136313953221/188072368028650199

https://surajitbrainwaves.blogspot.com/2024/06/nail-examination-another-prof-sn.html


He walked into a packed lecture hall of students, as rowdy as only they can be, with a smiling face and mesmerized them by his spell into pin drop silence. Then he would have a hearty laugh, as that was his way of greeting students and ask “So what are we studying today?” Anyone could suggest a topic from his or her wish list, even his own bunch of residents who would always accompany him, busy picking up the pearls of wisdom, which he so generously offered them from time to time. Someone in the class that day suggested ‘polydipsia’ and he simply took off right from there! This was his style. I have worked and studied in four continents and have never seen another teacher so spontaneous and yet so organized.

 

Drinking water is, of course, great for health and essential for our body. But if you’re constantly parched and thirsty, despite having 8-10 glasses of water every day, there may be a larger issue to blame. The simplest explanation for feeling thirsty is not drinking enough water. We usually feel very thirsty after spending a long day under the sun or after a hard exercise session. But endless thirst isn’t normal and shouldn't be ignored. 

 

“So, how much water does a human body need”, the professor asked. When he did not get a satisfactory reply from the class he said "we should aim for half of our body weight in ounces of water each day. For example, a person who weighs 140 pounds, which will be approximately 65Kg he should aim for about 70 oz or 2 liters or about 10-12 glasses of water every day. If you find that your patient’s water intake is around this recommended mark and he/she still feels thirsty, this is polydipsia and this should be investigated. Now what will happen to this excess of water in the body? It will naturally be converted into urine and expelled. So usually polydipsia is associated with  polyurea, or excessive urination". 

Let us understand the causes of polydipsia:


1. Dehydration

Dehydration means excessive loss of body water. It happens when your body loses more fluids than you take in. Therefore, you end up feeling overly thirsty. Dehydration can happen more easily if you have diarrhea, diabetes, heatstroke, or when you’ve sweat too much after exercising. It can also be caused by drinking too much alcohol. It is a constant feature of extensive burns. So, take note of this symptom and make sure your patient drink enough fluids if you’ve been suddenly dehydrated. If that is not possible then intravenous fluid replacement must be planned. This is urgent, and no time can be wasted. If the skin is dry, shriveled, textureless, the tongue is dry and the eyes have sunken in their orbital socket, your patient is in extreme dehydration and urgent rehydration is required.

 

2. Dry mouth or xerostomia

Dry mouth, also known as xerostomia, can often be mistaken for extreme thirst. It’s a condition where the salivary glands in your mouth don't make adequate saliva to keep your mouth wet. Xerostomia is usually caused by certain medications like Atropine or aging issues or as a result of radiation therapy for cancer. Other causes include smoking tobacco or marijuana, stress, anxiety, or aging. When our glands don’t make enough saliva, we feel the need to drink more water. If the feeling of a dry mouth persists first try prescribing sialagogues. These are of two types:

  • Peripheral sialagogues - Stimulate a gustatory response. For example, Amla or Indian gooseberry and lemon juice or lemondrops or pickles are sialagogues that promote saliva flow.
  • Central sialagogues - Include parasympathomimetics such as pilocarpine. Central sialagogues have more side effects than peripheral sialagogues.

 

3. Eating way too much salt

Just like it’s important to keep our sugar intake in check, we must also keep an eye on the amount of salt we consume every day. Our kidneys process excess salt and redirect it into our urine. When we eat a sodium-heavy meal, our kidneys have to work extra hard to get rid of the salt. Thus, you end up urinating more than usual. Overdoing it on sodium-heavy meals can also lead to high blood pressure over time and may cause kidney or heart damage as well. Adults should limit sodium intake to less than 2,300 mg per day – that’s almost 1 teaspoon of table salt. So check and see if your patient is going over this limit and cut down on their salt intake if needed.

 

4. Diabetes

Diabetes can increase your risk of dehydration. When someone has diabetes, their body doesn’t make enough insulin, and this leads to too much sugar (or glucose) building up in their body. The glucose in urine pulls in more water by osmosis, and hence, these patients are forced to urinate more often than usual. This makes them experience extreme thirst, as their body wants to replace the fluids it is losing. So, excessive thirst along with excessive urination and blurred vision, should always raise the red flag of diabetes.

 

5. Anemia

Anemia is a condition in which the body loses healthy red blood cells faster than it- can be replaced. This leads to a deficiency of oxygen in various organs and tissues of the body. While mild anemia usually won’t cause excessive thirst, severe anemia might lead to uncontrolled thirst. Anaemai is caused by underlying diseases, a poor diet, or heavy bleeding. Estimation of haemoglobin and study of the general blood picture establishes the type of anaemia and its cause can then be studied by detailed examination and investigations including urine and stool examination, liver, kidney and thyroid functions and endoscopies and radiological investigations.

 

6. Having too many diuretic foods

Diuretic foods and drinks can help you get rid of excess water and sodium from your body. They force the kidneys to excrete more sodium into the urine. As the sodium is flushed away, the body gets rid of water as well. Diuretics are usually prescribed when the body is retaining too many fluids. But overdosing on them will make your patient thirsty because they deplete the fluids in their body, causing an electrolyte imbalance. Some fruits and vegetables that act as natural diuretics include:- Pineapple- Watermelon- Cucumber- Celery- Cabbage- Beets- Asparagus- Watercress- Pumpkin seeds- Lemon. Commonly consumed diuretic beverages include coffee, tea, and lemon juice, among others. So, if your patient is having too many diuretic foods daily, it may trigger excessive thirst. Cut down on them a little to maintain a healthy balance.

 

7. Low-carbohydrate diets

Following a low-carbohydrate diet may be working wonders for your patient’s health, but it is likely to cause dry mouth and frequent thirst. That happens because carbohydrates hold on to more water than proteins or fats. When you stop eating carbohydrates, all the extra fluids get released through urination. Since your body is excreting more water, it causes a spike in your thirst levels. Thus, make it a point to drink enough water when you are following a low-carbohydrate diet.

 

8. Hyper-calcemia

Hyper-calcemia is a condition where the calcium level in your blood is above normal. Extra calcium in the body makes the kidneys work harder to filter it. This can make a person urinate more often, leading to increased thirst and even dehydration. Hypercalcemia can also cause stomach upsets, nausea, vomiting, bone pain, and constipation. Serum electrolyte estimation will diagnose this condition and it is easily correctable.

 

9. Chronic stress and anxiety

Chronic stress and anxiety may cause you to sweat, thus leading to serious thirst. Anxiety can cause dry mouth, and dry mouth can feel like thirst. Hence, your brain might be fooled into believing that you need to drink water even though you aren’t really thirsty. Also, chronic stress messes with your adrenal glands and can result in low blood pressure. This can then give rise to dizziness, anxiety, and extreme thirst, say health professionals. Thus, in case your patient has been unduly stressed about something, work towards managing it better.

 

10. Neuro-developmental disorders

Polydipsia can be a symptom of neuro-developmental disorders, such as autism and intellectual disabilities. 

 

11. Kidney diseases.

Chronic renal failure, urinary tract infection, and renal diabetes insipidus can cause polydipsia. DI can be caused by a number of conditions, including:

  • Central DI: The pituitary gland is damaged, which prevents it from producing enough vasopressin, a hormone that regulates water balance. This is often inherited in infants and children. 
  • Nephrogenic DI: The pituitary produces enough vasopressin, but the kidneys don't recognize it. This can be caused by inherited or acquired kidney disease, certain medications, low potassium levels, high calcium levels, or a blocked urinary tract.
  • Gestational DI: This is very rare. It's caused by the placenta producing an enzyme that breaks down vasopressin, or the pregnant person producing more prostaglandin, which makes the kidneys less sensitive to vasopressin.

DI patients, unlike Type 1 and 2 Diabetes Mellitus patients have normal blood sugar levels. Prompt diagnosis and treatment of DI is important to prevent severe dehydration, which can lead to brain damage or impaired mental function. 

 

That is how another Prof. Chakraborty’s class concluded. I would invite all his students, who routinely read my blogs, to contribute their own anecdotes about this wonderful teacher in the comment section.