I have been working late into the night with a lot of work.

Patients presenting with symptoms of swollen, painful bleeding gums can be analysed on the basis of clinical presentation, combined with personal experience and history of secondary disease.
If there is too much mental stress in a short period of time, it may lead to swollen and painful gums and bleeding symptoms may arise.
If one stays up late and lacks rest frequently, this may affect overall health and reduce resistance, leading to an increased probability of developing microbial infections and inducing symptoms of swollen, painful and bleeding gums.