FOR 13 years she suffered pain so severe that she spent most nights lying awake in tears.

Brenda Davidson's sciatica caused agony in her back, hip and leg - and strong painkillers did nothing to ease her symptoms.

But her symptoms virtually disappeared after taking drops of oil derived from cannabis plants.

Mrs Davidson says she is almost pain-free since taking a legally-available cannabis oil which contains no tetrahydrocannabinol (THC) - the psychoactive compound that causes a high.

She said: "It got to the point that I could no longer walk the dog. I would be in so much pain and just come home crying my eyes out. I have been on different painkillers over the years and they put me through physio but it did not really help."

Two days after taking her first drop of oil eight weeks ago, Mrs Davidson, 55, said she could not believe the difference it made.

The mother-of-three, originally from Kirkwall, Orkney, was on holiday in Italy 13 years ago when she began to feel pains that turned out to be the onset of sciatica.

The condition is caused by problems with the sciatic nerve which runs from the pelvis to the feet.

The former cafeteria assistant was informed about the oil's healing properties from her hairdresser.

She added: "My hairdresser has done a lot of research into the cannabis oil, and said her mother had seen tremendous results. She was putting three drops under her mother’s tongue and she reacted very positively to it.

"She told me that everyone will be different; it will depend on the individual. It is as if the pain has been switched off like a light."

The treatment has not yet been approved for use on the NHS, but is legally available online.

As a former cafeteria assistant, she was expected to be on her feet for long periods every day and this eventually resulted in her being unable to walk long distances at all.

She said: "If it does start to niggle a bit by tea-time I just take another drop and it’s fine again. I really did not think it would work, but it has."

"The NHS should definitely look into providing it on prescription – surely it would work out cheaper for them than giving out all these prescriptions for painkillers. Altogether, it is the best £54 I have ever spent."