You can't feel cells dying off. You can only feel nerves with intact connections to the brain. Apoptosis releases histamine and a cytokine response that causes pain in the nerves in that area. You can detect histamine response as rhinitis. Completed nerve death is perceived as numbness. I guess it's because there are a lot of cells dying off at once which is greater than the usual slow process. When this really gets going I have to use naproxen sodium to counter the cytokines, benadryl for the histamine and gabapentin for nerve pain (add acetaminophen when particularly bad). How do I know? The process sure acts like apoptosis. It can be inhibited by strong antioxidants or stopping the pro-apoptosis supplements. It leaves scar tissue behind. It improves Raynaud's disease temperature changes and reverses post-ME cold skin areas. Etc. To measure apoptosis: "In apoptosis assays, DNA fragmentation and sub-G1 phase populations were increased, and the mitochondrial membrane potential decreased significantly after treatments." https://www.ncbi.nlm.nih.gov/pubmed/26327534 So it looks like one needs to look at the cells microscopically. I would biopsy musculoskeletal cells in asyptomatic tender, weak muscles. Fascia, muscle and tendons. Test pretreatment reactiveness then re-biopsy post treatment and look for changes.