Physical Problems That Can Arise From Being Underweight

Updated April 13, 2017

If someone is underweight it means that they are not considered to be in a healthy weight range based on their body type, age, gender and height. Although the most common reason for being underweight is malnutrition because of lack of food, some people are underweight as a result of anorexia or bulimia, genetic predisposition, hyperthyroidism, cancer, liver problems, or other diseases or disorders. Physical problems can arise from being underweight.


For women who have issues being underweight, they may have issues with amenorrhoea, which is the absence of menstruation or missed menstrual cycles. Women who do not have a menstrual cycle may also have nipple discharge, migraines, changes in vision and excessive hair growth. A low body weight affects hormonal functions in the body, which halts ovulation.


Being underweight contributes to osteoporosis, which is a bone disease that reduces the body's bone density. This may lead to someone being more prone to fractures and the damage may become irreversible. If someone is underweight, dietary changes and exercises need to be addressed. Medications and supplements may also be prescribed, including vitamin D and calcium. Men and women with a small body frame are at increased risk for osteoporosis because they have less bone bass to draw from during the ageing process, according to the Mayo Clinic.

Heart Problems

Being underweight may result in cardiovascular issues and puts a strain on the heart. People who are underweight may have issues with loss of electrolytes and dehydration. Some people may be more susceptible to heart problems, particularly if they have high blood pressure or have lost heart muscle as a result of being underweight.

Type 1 Diabetes

Type 1 diabetes may occur in those who are severely underweight. Type 1 diabetes occurs when the body does not produce enough insulin. The body needs insulin to process sugar, which is the fuel for human cells.


Anemia is one of the main health problems that occurs in people who are underweight. People with anaemia have a lower number of red blood cells than what is considered normal, which can be caused as a result of a nutritional deficiency. Anemia may cause discomfort in the chest, fatigue and difficulty breathing because of shortness in breath.

Immune System Deficiencies

The body's lack of vitamins can have an impact on the immune system, making people who are underweight more likely to have colds. Nutrition deficiencies can affect how the body metabolises vitamins, minerals and antioxidants, which help protect the body against illness.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Andrea Helaine has a Bachelor of Philosophy in theology and is currently finishing her thesis course for a Master of Fine Arts in creative writing. Helaine has been writing professionally for over 10 years and has been published in several anthologies and is currently breaking into the screenwriting market.