Thousands of refugees in South Sudan need urgent medical help, says Samaritan's Purse.
The charity says there is "overwhelming demand" to treat thousands of patients in Maban County.
The region is home to more than 200,000 people, including over 110,000 refugees.
Conditions are "desperate", Samaritan's Purse reports.
The charity is appealing for funds to expand Bunj Hospital. It is the only medical centre in Maban County and was recently expanded to include a new ward and operating theatre.
Now there are urgent plans to expand the hospital further in order to treat thousands more patients.
Staff reporting working all day, seven days a week, and being "overwhelmed" by the demand.
"The hospital is beyond maximum capacity every day," said Samaritan's Purse UK's Head of Programmes and Projects, Chris Blackham, who just returned from visiting their work in South Sudan.
"They have plans to construct and add new facilities to expand the services offered to those in need – an x-ray ward, a further surgical theatre, a paediatric ward, a tuberculosis in-patient ward and another women's ward.
"These facilities will enable staff to provide life-changing treatment for another 175 people every week."