The unit machine numbers will increase from five to

14, with the ability to treat 36patients.

The hospital presently caters for 24 patients requiring dialysis.

People require dialysis when their kidneys stop functioning. The most common cause of kidney failure is diabetes.

Western Health spokesman Andrew Williamson said the organisation was the fastest-growing provider of dialysis services in the state.

There are 15 machines at Sunshine Hospital treating 76patients and four machines at Western Hospital treating 16 patients. There were about 10 patients living in the Williamstown area who were receiving dialysis at other hospitals.

"Many of these patients will be able to receive care in the expanded facility later this year," Mr Williamson said.

Construction on the unit expansion began in January and is due for completion in a few weeks.

Head of the nephrology unit Craig Nelson said it was better if patients did not have to travel distances after treatment as they often felt "washed-out".

Chronic disease and an ageing population in the western suburbs had resulted in a rise in the number of dialysis patients, he said.

"We had an increase in diabetes in the western suburbs, and 40 to 50per cent of people who start treatment here have diabetes."

During a visit to Williamstown Hospital last week, Health Minister Daniel Andrews said

the number of people requiring dialysis in Victoria had almost doubled in the 10 years to 2006. The state government provided $400,000 for the expansion, with the rest of the money raised by the community. The unit will be named the Wilson Renal Dialysis Unit after a $453,000 bequest from resident Robert Wilson.