When i shave the area under my chin and neck have always gotten red. how can i make it stop and go away?

Shaving irritation: Depends. If you are using a regular shaving blade, perhaps try a sensitive skin one. Or try using electric shaver most of the time and when using regular shaving blade, do not shave against the grain to try to get a cleaner shave, as this can cause irritation. Also you may consider a beard to give your skin a rest from shaving.

Laser hair reduction: This is a common problem in the military where shaving is necessary to maintain standards and laser hair removal treatments are frequent. Hair removal/ reduction through multiple laser treatments will cause the hairs to become less thick and less dense. Laser hair removal (in experienced hands) or growing out your beard are the best options when more conservative treatments fail.

Condition skin: Condition skin with showering or a warm moist washcloth to face for 5 min prior to shaving. Apply lubricating shaving gel (edge or aveeno (oatmeal)) or shaving oil and leave on for a few minutes prior to shaving. Use aveeno (oatmeal) PFB bump fighter razor or the flicker shave razor. Shave with the grain of the beard and do not stretch the skin. An electric razor may also help. See doctor if not improving.