I seem to get a mild headaches that last several days after lifting weights. They are not severe but they are a nuisance, its almost like a pressure more than a pain. The pain seems to be associated with a desire to pop my ears in a valsalva action. If I go a week or so without lifting then the pain goes away. There also seems to be tension in my neck area as well. I don't know what is going on. This happened a couple of years ago and I ended up having to stop lifting for months. I have been to doctors and they seem to be clueless. If anyone has any ideas I would love to hear them.

I had a similar problem where I would get a bad headache the day after lifting. I find that having a healthy snack and some water before and after your workout will keep your sugar levels balanced and you will be much less likely to get a headache afterwards. Also breathe during your workout and don't hold your breath while lifting which can raise blood pressure. Cool down after your workout.

The neck and headache may be related. This will sound crazy but it works. Press the tip of your tongue hard into the bridge of your mouth behind your upper teeth. Maintain the pressure through out the set. Doing this stops you from clinching your neck muscles during the lift.Also try dropping the weight to below 50% of your max and see if that allows you to contract only the muscles you are targeting while relaxing everything else except the core.