Welcome and thanks for posting your query to HealthcareMagic.
I can understand your concern for blood coming out of nose after simple blowing.
Generally blood coming out of nose is mainly because of any trauma to nose such nose picking or inserting finger in the nose which leads to trauma to the mucosa inside the nose. If the patient is not disturbing the nose then it should heals by 7-14 days. In your case it has progressed beyond 4 weeks so we should think of some other causes such as systemic one.
It can be due to some problem in the platelets ( the cells which prevents the extravasation of red blood cells from the vessels and forms the clot) or due to problem with the coagulation factors which helps in repair of the injury
to blood vessels and helps in clot formation.
At certain times there are certain medications which also can cause interference with normal coagulation mechanism. So if you are on certain medications then also it can lead to bruising.
For the best part of the diagnosis there are simple tests of platelet function and coagulation factors done routinely in all the simple laboratories to rule out the exact cause of the problem. If these tests are normal then you can rest assured and relieve your tensions regarding the bleeding part. Otherwise also if the test are abnormal then also can be very well treated without any problem. You can take second opinion
form another doctor to confirm the exact cause of the bleeding.
I hope these information's will help you. If you have further queries I will be happy to help.
"Wish you good health and early recovery from the problem"
Dr Sanjay Kumar Kanodia