Brief Answer: Indicative of an infection or abscess in lungs Detailed Answer: Hello, Thanks for your query. Presence of foul smelling mucus is indicative of an infection or abscess (collection of pus) in the lungs. As mentioned in your post, you have been diagnosed with Mono, which is a viral infection & reduces the immunity of the body. Because of this immuno compromised state, the body becomes susceptible to secondary infections, such as lung infection in your case. Investigation like complete blood count, X ray of the chest & culture & sensitivity of the sputum will be helpful in clinching the diagnosis. Management will involve a course of antibiotics based on culture & sensitivity reports. So, kindly consult your treating Physician & discuss regarding this. There is no need to worry, you will be fine. Wishing you a good health & speedy recovery. Please let me know if I need to clarify further. Take care.

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