After getting a few rounds of chemotherapy injections, many people feel at some point that their body is not as it used to be. They get short of breath climbing just a few stairs, they wake up in the morning feeling as if they hadn't slept, and their energy drains away even while sitting still. One person receiving lung cancer treatment said, "I used to be someone who climbed mountains well, but even doing one lap around the supermarket was a struggle." This is not because of becoming lazy; it is often the result of anemia caused by the chemotherapy drug also suppressing the bone marrow's function of making red blood cells, combined with the fatigue that the treatment itself places on the body.
Anemia and fatigue feel similar, but their causes differ a little. When red blood cells decrease, the power to carry oxygen falls, so you get short of breath, dizzy, and your face turns pale. On the other hand, the characteristic of chemo fatigue is that you don't recover even after sleeping. Add to that not eating well because of poor appetite, and breathing feeling even more labored because lung function itself is reduced, and a vicious cycle is created. So rather than brushing it off as "I'm probably just tired," it is good to observe your own body and note how severe it is. If something that used to be fine has suddenly become hard, you should see that as a signal.
What you can try in daily life is surprisingly simple. Rather than trying to rest the whole day at once, gathering the must-do tasks into the time when you have relatively more energy and resting the rest in short pieces tires you out far less. Lying down all the time actually makes muscles waste away and drains you more, so within a manageable range, keeping up walking around the house or a slow stroll helps. Eat iron-rich foods like lean meat, eggs, beans, and spinach a little at a time but often, and if you can't eat much at once, it's fine to split meals into several. A long empty stomach drains your energy even more.
And the important thing is that once anemia becomes severe, there is a limit to what lifestyle alone can do. If the hemoglobin level drops a lot, a transfusion may be given or an injection to help red blood cell production may be used; this is judged by the medical team while checking with regular blood tests. So at your appointment, describe specifically "how short of breath and dizzy you've been lately." With just one line of "I'm a little tired," it's hard even for the medical team to gauge how severe it is. Conveying everyday changes as they are — that you had to stop and rest on the stairs, or that you got short of breath while hanging laundry — becomes the most accurate information.
Finally, if your chest suddenly pounds, or you feel so severely dizzy that you might collapse, or breathing becomes noticeably harder, it is safer to contact the hospital right away rather than waiting for the next appointment. There are times when fatigue feels as if enduring it is a virtue, but during chemo that is not so. Honestly reporting the signals your body sends is the way to receive treatment well to the end. This article is only general information, so for what suits your own condition, be sure to discuss it with and decide together with your medical team.