One swollen lymph node for 10 days and congestion how long do they take to go down?

4-6 weeks. Enlarged lymph nodes can sometimes take 4-6 weeks to completely regress. After your symptoms are gone, it really should not get bigger. If it does, or if new ones appear, or if new symptoms (fever, fatigue, bruising, new cough, for example), you should see a health care provider.