When I was young my voice seemed normal but now I have a very nasaly voice & I sound like I'm always sick. What is causing this?

You have symptoms of posterior nasal obstruction, most commonly caused by enlarged adenoids. Often, however, existing nasal allergies, such as seasonal allergies can also lead to significant intranasal swelling and turbinate hypertrophy, which may also obstruct the nose. Occasionally, nasal polyps may also result in a nasally voice. Please see an ENT physician for a nasopharyngeal endoscopy. Good luck!