A misalignment of the C1 or C2 is known in chiropractic as a vertebral subluxation, or simply just a subluxation.
What makes a misalignment of C1 and C2 a subluxation and not merely a misalignment is that either vertebra can cause stress and tension on the ligaments inside the spinal canal.
Along with pressure on the nerves exiting the spinal column, as well as a dampening of the nervous system transmission between the brain and body, a vertebral subluxation is nothing to ignore.
Things like headaches, migraines, fibromyalgia, high blood pressure, sciatica, plantar fasciitis, and constipation often subside when a subluxation has been corrected.
Getting checked by a chiropractor regularly will minimize the length of time you have to put up with, or suffer from, a subluxation.