What doctors mean is the mass of a person in kg, not the weight. However, they use the colloquial term here, not the scientific one. This is not a problem as long as mankind is on the Earth. The weight depends only slightly on the location on the Earth's surface and is therefore directly proportional to the mass. It would be something else if there were doctors who had to give the mass of a person on the Earth and on the Moon. Colloquially it is called now once weight instead of correctly mass. No one would say "Mass Watchers" instead of "Weight Watchers". But with the "Body Mass Index" it is correct.

Thanks Sir Wolfgang R. Dick For your reply

"I appreciate the explanation. It's clear that doctors commonly use the term 'weight' when referring to a person's mass, even though it technically represents mass in kilograms. This practice simplifies communication, especially in everyday contexts where people are more familiar with 'weight' as a concept. While it might not align with strict scientific terminology, it is widely understood. The distinction between mass and weight becomes more critical in scientific and engineering discussions.

Hello Syed Zeeshan Ul Hassan

I think, seriously, it is easier for doctors and nurses to use kg because it fits in so easily with ml from fluid input and output - eg "The person has drunk 600 ml extra water today so their weight (theoretically) should go up by 600g."

Then their resident says "the person had a large amount of urine just before our ward round which was 200ml so therefore, they might only increase by 200ml."

Thanks Sir Joseph C Lee for your reply

it's important to clarify that weight and mass are indeed two distinct concepts. Weight is the force of gravity acting on an object's mass, and it's typically measured in newtons (N). Mass, on the other hand, is a measure of the amount of matter in an object and is usually measured in grams (g) or kilograms (kg) in the metric system.

In medical practice, we often use kilograms as a practical unit for measuring a person's mass because it aligns well with milliliters (mL) when tracking fluid intake and output. However, it's crucial to recognize that changes in weight may not always directly reflect changes in mass due to factors like fluid retention or loss. So, while we use weight as a convenient metric in healthcare, we should always keep in mind that it represents the force of gravity acting on a person's mass."

Sir my Question is that are Doctors are using right unit against weight or not.

Hello, again, Syed Zeeshan Ul Hassan

I agree with you that it is technically incorrect and I can see why it is always done incorrectly and will remain for a long time after now. Basically, doctors are poor in their understanding of physics!

Thank you Sir Joseph C Lee

For you reply And giving time to my Question.