Why Am I Losing Weight?


It could be that you have scales that you use to monitor your weight at home. Or you may be going by your looks or how tight or loose your clothes feel. But sometimes you notice a decline, and you ask, “why am I losing weight?”

Dear Reader you are worried because you are losing a lot of weight. Whether you are losing weight fast or slowly, does not matter. What matters is that you have lost significant amounts of weight, being 10% (ten percent) or more of your body weight.

And you are losing weight without trying. You are not on a weight loss program. You don’t have loss of appetite and are eating normally. Yet your weight is going down significantly and noticeably.

This article will lay out for you, the commonest causes of severe weight loss. The list is not exhaustive, but should provide answers for the overwhelming majority of people experiencing weight loss.


The gastrointestinal tract handles food from the point of intake, through digestion, to absorption. There can be pathology at various levels of the tract. This pathology will obviously interfere with the process of getting nourishment to the body’s cells.

For various reasons, people can have malabsorption syndrome. Malabsorption syndrome essentially prevents food, even if it is of adequate quality and quantity, to get to the body. This manifests as weight loss despite adequate food intake.

Malabsorption causes include

  • destruction of the gut flora by e.g. antibiotics
  • repeated or radical resective operations of the bowel

Another common and well known gastrointestinal disorder that can cause weight loss, is coeliac disease. This is a sensitivity to gluten, a protein found in grains.


This has among other symptoms, loss of appetite and loss of weight.

However, weight loss can occur in depression, without loss of appetite. There can still be adequate food intake, and yet weight loss occur. This is thought to result from the biochemical derangements caused by depression.


You could be losing weight because of a metabolic disease. This is what this and the next chapter deals with.

Metabolic disorders cause weight loss by a variety of mechanisms. We start by discussing thyrotoxicosis or hyperthyroidism.

Thyrotoxicosis is the excessive functioning of the thyroid gland. This excessive production of thyroid hormones, causes the body’s metabolic rate to be high. The high metabolic rate leads to breakdown of tissues, resulting in weight loss.

But thyrotoxicosis usually has other symptoms and signs. Top of that list is an enlarged thyroid gland, whether globally enlarged, or enlarged on one side. These other signs should alert sufferers of weight loss or their caregivers, to the underlying cause of weight loss.

There are other metabolic disorders that can present with weight loss. These include the inherited disorders of metabolism.


Diabetes, which causes abnormally high blood sugar levels, is a metabolic disease. It is very common all over the world. And it is increasing in incidence and prevalence.

Diabetes does have a collection of symptoms and signs that are well known. These though, are frequently absent or late to manifest. Significant, and often rapid weight loss, could be the only externally visible sign or symptom of diabetes.

In diabetes, the weight loss is often caused by loss of total body water. This is caused by the fact that sugar like other solutes, draws water wherever it goes. Water is therefore drawn out of the body’s cells, which may or may not result in excessive urination.


The Human Immunodeficiency Virus (HIV) is an ongoing pandemic. It is still very prevalent in some parts of the world.

At the onset of the HIV pandemic, what was noticed was an unknown disease that caused people to lose weight severely. The disease was indeed in Eastern Africa, called “The slimming disease”.

So yes dear Reader, unexplained weight loss can be a manifestation of infection with the Human Immunodeficiency Virus, HIV. And this certainly means that HIV counseling and testing services should be sought.

Early detection of HIV infection is now well known to have many benefits. There are many effective and safe treatment modalities, which are now instituted as soon as HIV infection is confirmed. This has a tremendous impact in prolonging life and improving the quality thereof.


Tuberculosis or TB is also still common, or even very common, in some parts of the world. It has indeed resurged over the last forty years, due to the HIV pandemic.

One of the classic and profound presenting symptoms of tuberculosis, is weight loss. The weight loss often accompanies cough, night sweats, lethargy. But weight loss in TB often occurs with severe anorexia (loss of appetite).


Cancer is a basket term for pathology that affects many organs and tissues. There are hundreds of different types of cancer. But all of them have as one of their classic presentations, weight loss.

The weight loss in cancer, just like in HIV and TB, is typically very profound. It is given the technical term of “cachexia”.


As can be seen from the foregoing discussion, weight loss, especially unexplained weight loss, can be a symptom and sign of disease. And the underlying disease can be very serious.

It is therefore advisable to never ignore weight loss. Timely detection of many of the conditions mentioned above can improve the chances of preventing morbidity or mortality from the disease.


Comments, questions or any contribution are very welcome and go a long way in improving this website that is at your service, Esteemed Reader.

You are assured of the Admin’s prompt, professional and compassionate response to your query or concern. Even comments that are not questions, do get immediate response and further input.

Kindly take a minute or so to share your thoughts and experiences on this or any other article on this website. And thanks in advance!

8 Replies to “Why Am I Losing Weight?”

  1. This is a very worrisome situation. Losing weight even without doing anything to make me lose weight will definitely get me super worried and anxious. Having read this article, I now have knowledge to detect or perceive what might be the reason for an automatic weight loss. I have never suffered from this before, but knowing more about it is a plus for me.

    1. Hi Nelson,

      Thanks for your input!

      Congratulations if you have never had unexplained weight loss man! It tells me you have had an awesome, worry-free life! 😁

      You are right, being equipped with knowledge for future reference is always good.

      Warmest regards!

  2. Thank you,

    Most of us spend so much of our lives worried about weight gain so it is lovely of you to have shared some of the issues facing people who are losing lots of weight quickly. 

    I went through this when I was experiencing a huge amount of stress and it can be awful. Initially I enjoyed losing the weight until I started to look like a “skeleton” and it made me quite ill. Important for anyone experiencing this to get checked out by your doctor sooner rather than later. 

    Great article


    1. Hey Imelda,

      Thanks so very much! It’s as if you read my mind. 😁

      I actually wrote this article because in August, I have written three detailed articles about obesity and overweight. So I felt bad because I knew there was the other side of the coin: people who are struggling with losing too much weight.

      I am glad you came out of the uncomfortable situation you were in. And I am sure you have come out STRONGER.


  3. I have never really taken a serious look into losing weight before. I mean don’t we all love losing a few pounds? Lol Anyways, thanks for sharing such an informative post. It can be alarming when you lose weight and do not know the cause. That I understand – it happened to me once. When I am really depressed I do not have an appetite but I think that I eat enough. In reality I did not eat at all. That can be risky and harmful if you live by yourself. Thanks for pointing these issues out. 

    1. Hi Nuttanee,

      Thanks ever so much!

      It is very advisable to have a support system when dealing with depression. Get family and friends to watch over you, even if they are far (you know the modern means of doing that). In that way, you are unlikely to harm yourself including by starving yourself. Good friends will always take a friend who has lost appetite for food and usual activities, out to eat. Or they could bring them food.


  4. Great article Dr Teboho,

    I never knew depression can cause weight loss! I’ve recovered from depression but I do have huge amounts of stress which would make me eat a lot and become tired earlier at night. I’m not sure why but I think it’s due to the energy and focus of the body to the stress. Does stress effect weight loss too?

    1. Hi Riaz,

      Thanks so very much!

      Depression can affect weight in both directions: up or down. In the case of weight loss, people usually get this because of poor appetite. But there can still be a normal or even excessive appetite, and yet weight loss occur! This is due to a variety of factors, including the frequent occurrence of poor sleep. Staying awake too many hours per day, is one of the reasons for weight loss in depression.

      “Stress” is a term that people often use to describe negative stress or distress, which is in essence a precipitant or of depression (or accompaniment thereof). So yes, stress can affect body weight, including causing weight loss. I would strongly advise you break the cycle of feeling negatively psychologically (stress) and eating. You may need the help of a Clinical Psychologist if you cannot do it on your own.

      Warmest regards.

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