Optimizing Mastitis Identification and Treatment

The goal of this observational study is to gain more information about the aetiology and progression of mastitis and breast inflammation, in order to develop evidence-based clinical guidelines and treatment plans, especially concerning judicious use of antibiotics. The main questions it aims to answer are: * Do clinical symptoms differ between inflammatory and infectious mastitis? * What is the microbial composition in human milk, and does it change before, during, and after episodes of mastitis? * Does the bacterial composition change due to antibiotic treatment? * Are all mastitis episodes treated with antibiotics bacterial mastitis? * Do mothers with recurrent mastitis have a distinct microbial composition? * Are there immunological markers that can differentiate between bacterial and inflammatory mastitis? Researchers will compare breastfeeding women with and without mastitis to see if the microbiological composition in milk and on the skin of the breast and breast nipple differs.