Doctors donât know exactly what causes migraines. It appears that migraine headaches may be caused in part by changes in the level of a body chemical called serotonin. Serotonin plays many roles in the body, and it can have an effect on the blood vessels. When serotonin levels are high, blood vessels constrict (shrink).
Average Salary. The average annual salary for physical therapist in the United States is $86,520, which is 103% higher than the average income of Americans. The median pay for PTs is $7,210 per month, $1,663 per week and $41.59 per hour.
The average hourly wage of a Physical Therapist Assistant in the US is $26.56 per hour. Salary range. Salary can range quite significantly depending on where you live and how much experience you have. There is a significant range in average earnings from a low of $32,640 to a high of $76,940.