Dreaming of bad odors signifies hearing negative talk or feeling mental pressure. Particularly, if the smell resembles that of armpits, it may indicate symptoms like headaches, nasal congestion, or a cold. This suggests that some negative aspects or situations in your life are affecting you, potentially impacting your mental health.
From Imam Muhammad Ibn Seerin's Dictionary of Dreams According to Islamic Inner Traditions â entry "Odor" (page 308).
Smelling a bad odor in a dream means hearing bad words, or it could mean distress. Smelling odor that emanates from under the armpit in a dream means headache, nasal congestions, cold, or hearing bad news, divulging secrets, dis pelling rancor and jealousy, or it could mean relaxing after an exhausting workday, contracting an eye disease, or it could mean loathsomeness. If a child smells such an odor from under his armpit in his dream, it means that he has reached his puberty, or it could mean an illness or an accident that could take away his life. (Also see Cloud of smoke; Perspiration; Smell)
Note: Islamic dream interpretation depends on the dreamer's circumstances and state. This is a general guide drawn directly from the source book.