Do you know your instrument's "bad" notes? Are they getting worse? Playing softly?... especially in the low registers a problem? Is your instrument breaking down more often? Do you have intonation problems or has the intonation changed since you received the instrument?
If you answered YES to one or more questions, it is probably time to take your instrument in for periodic maintenance and/or repair. Your woodwind is a mechanical device and, like all devices, it does require periodic care by a qualified technician.
Notwithstanding emergency problems, we highly recommend taking your instrument to a qualified repairman ANNUALLY -- we strongly encourage, a NAPBIRT technician [n.b. NAPBIRT = National Association of Professional Band Instrument Repair Technicians; see link at bottom right in RESOURCES].
Also, while you're here at our website, we invite you to read some of the article, Deterioration of Grenadilla Instruments? Specifically Part 1 of that article? Please click on PUBLICATIONS and then on the article in question. Part 1 deals with one of the most extreme problems you may confront.