A new smartphone app to help women diagnose a urinary tract infection (UTI) is being trialled by the NHS.
The app will be overseen by 37 pharmacies in a trial across Nottinghamshire and Derbyshire, aimed at freeing up GP appointments.
It guides users through a urine test and allows the results to be analysed online by a pharmacist.
Suspected UTIs make up 3% - 10.2 million - of GP visits in England, costing the NHS about £316m in GP time.
The infections affect about 15% of women each year, the NHS said.
After speaking to a pharmacist, a woman may be given a home-testing kit, instead of being referred to their GP.
A dipstick is placed in urine, then put on a colour board, which is used as a reference point for the patient's smartphone camera.
This image is then checked by a pharmacist for signs of infection and antibiotics prescribed if necessary.
Sid Dajani, a pharmacist and adviser to app developer Healthy.io, said: "If only one in 10 women with a UTI was treated in a pharmacy instead of their GP, the NHS would save £28m a year in England alone.
"And there would be millions more appointments available for more serious or urgent problems."
Dr Ken Deacon, medical director for NHS England in the Midlands, said: "This innovative pharmacy scheme offers rapid relief for women while freeing up GP appointments.
"Under the scheme, women who don't test positive for a UTI will have a follow-up consultation.
"This allows the pharmacist to explore further the possible causes of their symptoms and discuss treatment or a GP referral."
The trial will run to the end of the year.