Hospital clothing is usually loose fitting so that bed ridden patients can be cleaned and examined easily.
A hospital gown is usually worn by male and female patients when in their bed.
Hospital pyjamas are more similar to pyjamas you might wear at home. They have a loose fitting top with long sleeves, and loose fitting trousers. All hospital clothing is made from soft cotton.
The name for clothes patents wear in hospital is: a hospital gown.
"Mark wore a hospital gown as he waited on a patient trolley outside the operating theatre."
病院で患者が着る衣服は 'hospital gown' と呼ばれます。
"Mark wore a hospital gown as he waited on a patient trolley outside the operating theatre."
(手術室の外、ストレッチャーで待つマークは病衣を身につけていた)
"Hospital gown" and "Hospital Pajamas"
These two expressions/terms are used to describe the clothes given to a patient at hospital, the gown often refers to a one piece of clothing that covers the whole body, pajamas is the term used as the clothes you would wear when you go to sleep.