There are various side effects, some of which are worse if you undergo a longer radiation schedule as opposed to a shorter one. On September 15th I finished 20 sessions over the course of 4 weeks to my chest, armpit, and neck. Towards the end of radiation I was getting pretty tired. About a week or so after I was done I was even more tired. I was taking 1 or 2 naps a day at first. Then I tapered down to 1 nap every other day around mid October. Since Halloween I've been taking 1 nap a week. At this point my energy is starting to return to a fairly normal level for the first time since this latest round of breast cancer which included 3 surgeries and 8 rounds of chemo in addition to the radiation since last November. I've had radiation 5 times now and it always gives me a gross metalic taste that starts from the first radiation session. I also get nausea from radiation. It seems to ramp up between the 1st and 2nd week and lasts until I am 1 to 2 months post radiation. You will want to apply lotion to the areas that are radiated. The radiation dries your skin out, can cause burns, and can change the color and texture of your skin. When I've had radiation for a week/5 sessions my skin got a little red, but that was it. When I've had radiation for 3 and 4 weeks my skin blistered, burned, and peeled. That started about a week after I finished radiation and took about a month to clear up. It's 2 months since I finished and my skin is still drier than normal and the texture is changed somewhat so I keep slathering on the lotion. The radiation to my neck area gave me a sore throat that starting around the 2 week mark. It hurt to swallow and to eat. It got worse during the 3rd and 4th week and cleared up about 3 weeks after I was done with radiation. It helped to eat foods that were soft like pasta and mashed potatoes. Ice cream, pudding, and jello were soothing. I tried to avoid foods that felt rough and scratchy. That was pretty much anything fried, crunchy like chips or crackers, meat, bread, etc. Carbonated drinks were painful so I drank water, juice, and milk. Hope this helps. Good luck with your radiation treatments. ❤️