Impaired sense of smell and taste can be due to many things. The most common causes are nasal congestion or swollen mucosa in the nose. It can also be due to a damage to a nerve or to the brain.
Here you can read more about diseases and problems in the nose. But also about problems that affect the sense of smell.
Nosebleeds are common and are due to superficial blood vessels in the nose. The bleeding can start on its own if the mucous membranes are dry or have become inflamed by a cold. Often the bleeding goes by itself but sometimes you need care.
A nasal polyp comes from the mucous membrane of the nose and looks like a small stalk or bud. You can usually not see if you have nasal polyps yourself because they sit far into the nose. Small polyps usually do not cause any symptoms at all, but if the polyps become larger you can have problems especially with nasal congestion.
Nesting and sniffing are common. Often this is due to a cold, but it can also be due to allergies, sensitive mucous membranes, pregnancy or that you have used nasal spray for a long time. Often it goes away by itself but sometimes you need treatment.