Mastitis is the answer. One of your breasts is engorged. There is a slightly red patch which is painful to touch. When the baby feeds it's extremely uncomfortable. After the feed your breast feels sore. You dread the next feed... and then you begin shivering. You think you have the flu. You have hot and cold sweats. You have a thumping headache. You retire to your bed and feel utterly miserable. Visitors encourage you to give the baby a bottle so you feel like you've failed... but there is a solution.

In most cases mastitis affects only one breast at a time. So what causes it?

Most often a new mum, whether or not she has previously breastfed, will suffer mastitis as a result of incorrect positioning or latching on of the baby. Consequently the milk is not properly drained from the breast and a milk duct becomes blocked. Other reasons include skipping feeds because you don't want to feed in public or in front of visitors, or the baby is sleeping and you do not want to disturb him.

If you recognise the sensation of a blocked milk duct you may be able to avoid it progressing into mastitis by gently massaging your breast in the bath or shower. Massage downwards towards the nipple. You may feel a small lump which disappears as the duct becomes unblocked. You can also try feeding the baby more often and again massaging the sore area towards the nipple as the baby drinks. Another effective technique is to try expressing milk with the aid of an electric or hand pump. However, if all your efforts are in vain and the duct does not unblock mastitis will often follow. Mastitis is simply when the blocked duct becomes inflamed and possibly infected.

Current medical advice is to continue feeding from the affected breast even if it is infected. The infection will not harm the baby. However, the last thing you may want to do is to feed from the affected side at all as it is so painful. This will only make things worse and you may end up with an abscess. If this happens you will need to have the abscess drained by a doctor.

If you are worried about your baby drinking milk from the affected breast a good alternative is to express and dispose of the milk and to feed only from the unaffected side. Your body will adapt. It will continue to supply enough milk for your baby from the unaffected breast. And as long as you express regularly from the affected breast the milk supply will be maintained. You produce breastmilk on a supply and demand basis so there will always be enough. When the infection clears up you can simply return to your usual feeding pattern.

If you do get mastitis and it does not clear up within a few hours you will probably require an antibiotic so speak to your GP. Make sure to tell him you are breastfeeding so a suitable antibiotic can be prescribed.

To avoid a recurrence make sure you position the baby properly. Ensure he is not sucking on just the nipple but that he has a good mouthful of the areola also. Try to sit upright or if lying down do not lie on the breast. Make sure the baby is tummy-to-tummy with you, his nose and mouth facing the breast and that he is not creating a blockage with his chin or a hand or arms.

Mastitis usually clears up completely within a couple of days so put it in perspective. Don't give up breastfeeding because you have mastitis. Instead ensure you don't get it again; position your baby correctly, feed on demand and avoid skipping breastfeeds.