Nosebleeds can be caused by bad habits, environmental factors, rhinitis or certain systemic diseases. 1. Bad habits: often rubbing the nose or picking the nostrils with your hands in daily life can easily lead to damage to the nasal mucosa and cause bleeding. 2. Environmental factors: dry weather or less drinking water leads to dehydration of the nasal mucosa, nasal capillaries are more fragile, it is easy to appear nose always nosebleed. 3. Rhinitis: Nasal inflammation can easily stimulate the nasal mucosa, leading to vasodilatation of the nasal mucosa, causing capillary rupture and thus nosebleeds. 4. Systemic diseases: such as thrombocytopenia, thrombocytopenia leads to poor coagulation function. Normal people have platelets on the blood vessel wall, which can effectively prevent bleeding. However, if platelets appear to be reduced, the hemostatic function of the blood vessel wall will be damaged, and the coagulation function will also decline. That’s what causes blood to flow out of the blood vessels and nosebleeds to occur. There may be other reasons for nosebleeds, so it is recommended to go to the hospital as soon as possible for examination and diagnosis to clarify the cause of the disease, and according to the doctor’s guidance for targeted treatment to avoid aggravating the symptoms and causing adverse effects.