6 doctors weighed in:

Can being underweight cause tiredness and exercise intolerance?

6 doctors weighed in
5 doctors agree

In brief: See below: Yes

Underweight might be secondary to or symptomatic of an underlying disease.
Unexplained weight loss needs evaluation asap. Severely underweight individuals may have poor physical stamina and a weak immune system, leaving one open to infection. Malnutrition due to poor/inadeq intake, genetics, underlying mental or physical disease need to be ruled out.

In brief: See below: Yes

Underweight might be secondary to or symptomatic of an underlying disease.
Unexplained weight loss needs evaluation asap. Severely underweight individuals may have poor physical stamina and a weak immune system, leaving one open to infection. Malnutrition due to poor/inadeq intake, genetics, underlying mental or physical disease need to be ruled out.
Dr. Michael H. T. Sia
Dr. Michael H. T. Sia
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