What causes slurred speech upon waking?

Slurred speech upon waking can be caused by several factors, including sleep inertia, dehydration, or residual effects of alcohol or medication. During sleep, the body may become dehydrated, leading to temporary muscle weakness, including in the tongue and vocal cords. Additionally, if someone has just woken up from a deep sleep, they may experience cognitive grogginess, which can affect speech clarity. In some cases, underlying medical conditions such as stroke or neurological disorders may also contribute to slurred speech.