NECK pain, back pain, bad posture and even digestive problems. Did you know that all of these things can be symptoms of wearing the wrong bra size?

On top of that a bad bra can make your boobs sag by as much as 10cm.

A study by lingerie brand Bravissimo found that 80 per cent of women are wearing the wrong-sized bra and many buy bras that are too small for them because they can't find attractive ones in larger sizes.

Osteopath Richard Moore, of Moore Osteopathy in West Bridgford and Ruddington, says he regularly sees women who are experiencing a catalogue of health problems due to wearing the wrong sized bra.

"I see a lot of people that have neck, shoulder and back pain from an ill-fitting bra. You can definitely draw a connect between the two," says Richard.

He says that a badly-fitting bra, especially one that's too tight on the back, can cause a women to slouch and stoop. This can cause aches and pains in the neck and back and even problems with digestion and breathing.

"Often what happens is that the chest width – so the number part – is too tight. It compresses the lower ribs and stops them moving when you breathe," says Richard.

"The opening and closing of the ribs when you breathe helps to improve flood flow to the area of digestion.

"Also, if it's too tight in terms of the shoulder straps, it tends to pull you forward and that affects the mobility of your stomach contents flowing through quite so well. It makes you more prone to constipation and a slow digestive tract which are often symptoms associated with irritable bowel syndrome (IBS)."

Signs of an ill-fitting bra include red marks left on the shoulders and on the back where the clasp is, the straps falling down, the band at the back riding up, 'side-boob' caused by it being too tight and boobs spilling over the cups.

When buying bras, the temptation can be to go for the prettiest one on the shelf, but Richard advises to go for practicality over prettiness.

He says: "The more supportive ones are often the larger ones with bigger straps which people don't always want, but when you think you're wearing it day in, day out, function is the important thing."

Another problem with ill-fitting bras is sagging , especially when doing sport. It's estimated that of the 12 million British women who regularly exercise, three quarters don't wear the correct bra – even though they can reduce bounce by up to 74 per cent.

Claire Hill, assistant manager of sportswear shop Sweatshop, in London Road, says: "It's really important to have adequate support when doing exercise. If the bra's not supportive enough, what will happen is the bouncing action will cause the Cooper's ligaments (connective tissues in the breast) to go and they can't be repaired. If it stretches then your breasts will sag. If you are bouncing around then it can also hurt at the time."

Surprisingly, osteopath Richard believes that the new £1 bra launched by Poundworld could be the answer to a lot of bra problems.

The new bra, which sold out in one weekend with 100,000 flying off the shelves, steps away from the traditional design of separate cups, straps and clasps, instead going for more streamline, one-piece design in a stretchy material.

Richard says of the bra: "I actually think it's quite a nice design. It's made of a cheap material and doesn't stretch particularly well and it's only available in three sizes – small, medium or large – but if it was made a bit better and was available in different sizes then it would be great.

"It doesn't have the underwire which can compress the tissue underneath and cause damage, there's no pressure points such as a clasp for it to hinge around. If it was somehow more supportive it would be great. In theory it's a nice idea."

After selling out of the £1 'comfort bra' earlier this month, Poundworld says it's planning to roll the bra out to all of its stores.

Chris Edwards junior, trading director at Poundworld, says: "We're confident that there is no other product like this available on the market worldwide at the same incredible value.

"Due to its runaway success, we predict we'll sell over one million in the next few months."