It is not uncommon for a mother to be concerned about being in contact with her baby when she is sick. It can be reassuring to know that continuing to breastfeed your baby while sick with "normal" illnesses such as a cold, sore throat, flu, fever, breast infection, etc., is the best thing you can do for your baby.
Your breast milk will have specific antibodies in it for that particular illness, which helps prevent your baby from getting sick, or if he does get sick, it'll be a much milder case. Also remember that your baby has already been exposed to the illness before you even knew you were sick.
Breastfeeding will not weaken you if you are sick. To conserve energy, you may want to try bringing baby to bed with you and nurse her lying down when she is hungry. Then if possible, have someone else change and entertain the baby while you rest. Illnesses are generally transmitted through skin contact and secretions from the nose and mouth, not through breastfeeding. When you're sick, good hygiene can also decrease the chances of baby catching whatever illness you have. Regular hand washing and limiting face-to-face contact are also helpful.
When you have a cold or flu, you should treat only the symptoms you have. Drugs available over the counter for coughs, colds and allergies are often found in combination formulas. These should be avoided during breastfeeding, whenever possible. Usually one or two symptoms are the most bothersome, and a single-ingredient product could treat them effectively. Also, avoid oral sustained-release products.
Use caution in taking antihistamines or decongestants. Most are safe, but many may affect the milk supply. Antihistamines can cause drowsiness and fussiness in your baby as well. Your milk supply could decrease with high doses, or if combined with a decongestant. Use them no more than necessary to control symptoms; often a single dose at bedtime is enough.
Decongestant nasal sprays are preferred over oral ones. Some oral decongestants can have the same side effects as antihistamines. Steam inhalations can also be helpful in relieving nasal congestion. Products with menthol and essential oils such as eucalyptus are often helpful.
If your doctor prescribes any medication when you're sick, remind him that you are nursing, so the doctor can prescribe something that is compatible with breastfeeding. Most medicines are safe to take while breastfeeding, and for those that not recommended, there is almost always an alternative.
Visit the TOXNET website for a peer-reviewed and fully referenced database of drugs to which breastfeeding mothers may be exposed. Among the data included are maternal and infant levels of drugs, possible effects on breastfed infants and on lactation, and alternate drugs to consider. The database is provided by the United States National Library of Medicine.
Many times moms don't nurse often enough and don't drink enough fluids to maintain their milk supply. Remember to drink plenty of liquids to avoid dehydration and continue to nurse your baby often.