That could be serious things such as a stroke to non-serious things such as Bell's Palsey. Many of the causes are treatable but time is of the essence to you should see a doctor immediately.
Lack of its needs, water, sunlight...etc.
Something is happening in the growth.
A Stroke!! see a dr!
Smooth muscles
Going into the shade.
allergic reaction
The first possibility would be a lack of water. followed by bad draining, or root diseases
The cells lose water and become flaccid, which in turn causes the entire flower to droop (or 'wilt')
Evan droop his head.
why do plants droop when no water
The shadow on above lip or dark skin on upper lip causes waxing or exposure to the sun, for women it will be experienced during or after pregnancy. It causes hormonal imbalances for women after taking pills and allergic reactions to make up, cosmetics, and medications.
When the water of the plant is sucked out of the plant, and the plant doesn't have anymore water so the leafs droop!