Head-up Tilt Sleeping to Alleviate Orthostatic Hypotension, Supine Hypertension and Nocturia in Parkinson's Disease

Whole-body head-up tilt sleeping (HUTS) will be carried out in three different angles, each for the duration of two weeks. Prior to the first angle the participant will sleep in a horizontal position for 1 week. The different angles will be installed using a wedge between the mattress and bed frame.