Hello doctor, i have this weird aching mild pain in my lower back side of the head on both sides. i noticed it usually happens at night.

Occipital neuralgia : Pain in lower back of head can be due to irritation of occipital nerves. Usually self limiting, can involve pain in neck, increased by movement and in night.

Head pain: Nightly mild or dull ache in the lower part of the back of the head is often the result of muscle tension from stress. This stems from the tension that builds up in the neck muscles. Of course before we can rule out other causes like arthritis of the neck vertebrae we would examine you and measure your blood pressure. If the problem is chronic stress , stress management therapy would help.