Inversion therapy involves being upside down or at an inverted angle with the intention of therapeutic benefits. The process of doing so is called inverting. This can be done via hand balancing (such as in a handstand) or via hanging.
When the body's weight is suspended from the lower body – rather than borne on the hands as in handstands or headstands or hanging from a bar with arms at sides, which are also forms of inversion – the pull of gravity may decompress the joints of the body below the anchor. Hanging by the feet, as with gravity boots or inversion tables, causes each joint in the body to be loaded in an equal and opposite manner to standing in an identical position of joint alignment. Inversion therapy of this sort is often commercially advertised as a relief for back pain.
Health risks 
People who have heart disease, high blood pressure, eye diseases (such as glaucoma), or are pregnant are at higher risk for the dangers related to inversion therapy and should consult their doctors about it first. The first time anyone tries inversion therapy with gravity, they should be sure to have someone standing by, in case assistance is required to get out of the apparatus, or if health problems are experienced.
During an episode of acid reflux, small amounts of stomach acid manage to escape out the stomach's doorway and into the esophagus. Fortunately, gravity keeps much of the stomach acid away from this doorway. However, in an inverted position, gravity cannot do its job. Combining an inversion table and acid reflux can be a painful, nauseating and potentially dangerous combination.