HI, thanks for using healthcare magic
The burning sensation in the stomach may be due to GERD (gastroesophageal reflux disease
). This is treated by altering lifestyle changes and medication.
The lifestyle changes include reducing the use of fried/fattly/spicy/acidic foods.
There are different causes of headaches
and if they are persistent you should visit your doctor for an evaluation. The most common types of headaches are tension headaches, migraines, sinus
Pain in the knee may be related to the joint or surrounding muscles. One of the more common joint conditions would be osteoarthritis
I hope this helps