Why Does Lung Cancer Cause Weight Loss?

Weight loss is quite common in people with lung cancer. Even sometime it can be one of the early symptoms of the disease, though many times this cancer doesn’t cause early signs and symptoms. And there are several reasons of why lung cancer can cause weight loss.

Weight loss is common in many cancers

Unintended weight loss can be abnormal, especially if it occurs without known cause. Unfortunately, it’s not always easy to find the underlying cause of the problem.

image_illustration389In fact, it s also attributed by lots of factors! There are many conditions that can contribute to cause weight loss. In other words, it can be a symptom of numerous different conditions – and one of them could be cancer.

However, in some cases it is caused by minor condition that even may improve without treatment. But in general, you should see a doctor promptly if you lose more than 10 pounds without trying!

Weight loss problem can be found in about 40 percent of patients with cancer. Even for those with advanced cancer, most of them have it.

In cancer, it usually occurs together with other similar symptoms such as lack of energy (fatigue), weakness, and difficulty in daily activities. Though it is very common in cancer, but this may be not fully understood yet.

However, some theories have been proposed. If you have cancer, your cancer may use up much of energy, and as a result you can be easier to have lack of energy.

At the same time, you have loss of appetite. You tend eat less than usual and cannot replace the energy that you have lost. These result in abnormal weight loss!

Why does lung cancer cause weight loss?

When the cancer is still too small and completely in the lung (it doesn’t spread yet), lung cancer is less likely to cause symptom including weight loss.

As the cancer grows, it will be more intense in affecting the lung function or other parts of the body. For more information about the symptoms of lung cancer, see this section!

In a few cases, early cancer in the lung may have caused some early symptoms and one of them could be weight loss. For such cases, patients are more likely to seek help and lung cancer may be caught early.

Weight loss in people with lung cancer can occur in a number of different ways.

The following are some helpful explanations!

The high demand on using the energy

In essence, weight loss related to cancer occurs because the demand of using energy increases significantly but you cannot replace the energy that you have lost!

Theoretically, you will lose weight if the calorie or energy that you eat from food is lower than what you burn (use). And if you have cancer, your body works harder to fight against the cancer. The cancer itself may also use up of much energy to grow and develop, as noted before.

These can cause a significant increase in the demand of using your energy. And at the same time, it’s always not easy to eat as well for people with cancer. For instance, decreased appetite or even appetite loss is a common symptom in lung cancer.

Appetite loss

Your appetite plays a key role in your diet. If you have poor appetite, you can find foods unappealing and you are likely to eat less. And as a result, weight loss occurs.

In lung cancer, appetite problem can be attributed by a number of different things, from cancer itself to the cancer treatments.

For instance, there is a chance for the cancer to affect your metabolism. And this may contribute to decrease your appetite. Pain in lung cancer is also common, and this symptom may also affect your appetite.

Furthermore, other side effects of some treatments for cancer may also contribute to affect your appetite.

Your shortness of breath may also have an effect on your weight

As well we know that breathless or shortness of breath is very common in patients with lung cancer. Even it is one of the most common symptoms.

The cancer grows in the lung and it can affect many functions of the lung. Even if necessary, one lung can be completely removed with surgery in order to remove the cancer tumor. And breathing with one lung is more difficult!

All of these can cause difficulty breathing. You can use more energy just for breathing.

Normally, you only need about 100 calories per day to use your lung for breathing. These calories are required to expand and contract the muscles involved in breathing. But this number can increase quite high if you have lung cancer. This extra work can slightly contribute to cause weight loss, too.

Metastasis of lung cancer

Why is weight loss more common in advanced stages?

When the cancer has become advanced, more energy required by the body to fight against the cancer. Advanced stages means there are more areas of the body affected by the cancer, and this can drain your energy more!

Metastasis of lung cancer can be another answer. For instances: