Not everyone responds to mold exposure the same way. Symptoms range from mild to severe. Children, older adults and immuno-compromised individuals are at greatest risk of developing problems. People with severe mold allergies can develop fever or shortness of breath. Symptoms can include: sore throat; bleeding gums; runny, itchy or stuffy nose; nose bleeds; difficulty breathing; wheezing; coughing; swelling of the lungs; and even bleeding in the lungs. A rare inflammatory lung disease called hypersensitivity pneumonitis. can also be caused by mold exposure.