Bedridden
Being bedridden is a form of immobility that can present as the inability to move or even sit upright. It differs from bed-rest, a form of non-invasive treatment that is usually part of recovery or the limitation of activities. Some of the more serious consequences of being bedridden is the high risk of developing thrombosis and muscle wasting (atrophy). Its meaning is derived from a middle English term (bedrid) from a 1300s past tense form of riding a bed.
Wikipedia
Bedridden (adjective)
confined to bed because of infirmity or illness
Bedbound (adjective)
Unable to leave one’s bed for some reason.
Wiktionary
Bedridden (adjective)
confined to bed by sickness or old age.
Oxford Dictionary