When hot weather continues, it's easy to feel drained even if you haven't done anything. You might dismiss it as simply being tired from the heat.
However, if you've rested and slept enough but still feel exhausted, it's worth looking into other reasons. If you feel dizzy, get out of breath with minimal movement, and your face is pale, it's a good idea to check for anemia.
A state of insufficient oxygen delivery
Anemia is a condition where tissues don't receive enough oxygen due to a lack of red blood cells or hemoglobin. Since delivery is delayed, even the same tasks feel more difficult.
You might experience shortness of breath when climbing stairs or walking quickly, heart palpitations, headaches, or dizziness. However, these symptoms can also occur due to dehydration from heat, lack of sleep, or overwork, so they cannot be distinguished by symptoms alone.
It's not just an iron problem
While anemia often brings iron to mind, there are several types. Iron deficiency anemia, caused by insufficient iron or iron loss from the body, is the most common. It can also occur due to a lack of vitamin B12 or folic acid. It can also appear in chronic diseases or kidney diseases.
In women, it can sometimes be caused by continuous iron loss due to heavy menstrual bleeding. Conversely, if it recurs without an apparent reason, it's important to check whether there might be slight bleeding from the gastrointestinal tract.
The order of checking
Blood tests first check hemoglobin and red blood cell counts. If anemia is confirmed, the cause is determined by adding iron status, vitamin levels, and kidney function.
Even if you receive an anemia diagnosis during a check-up, it's better to first identify why the levels are low rather than immediately taking iron supplements. Different causes require different management.
Reviewed by: Dr. Kim Seonhoo · Gastroenterology Subspecialist, Digestive Endoscopy Specialist Last reviewed on 2026-09-02
This article is intended to provide general health information, and the cause and necessary tests may vary depending on an individual's condition. If symptoms persist, please consult with a medical professional for diagnosis.