There are 4 ways to know if your voice is in good condition
1. Are you constantly hoarse or clearing your throat throughout the day?
2. Do you drink more than two glasses of wine, beer or spirits / day?
3. Do you suffer from regular sore throats?
4. Do you easily catch colds, flu or suffer from high build up of mucus in your sinuses?
If any of these affect you and you use your voice regularly for presenting, singing, acting, or for your work or business, its time to take a long hard look at what you eat, drink and whether you smoke or drink. in other words those areas that directly affect health and therefore your voice and its ability to function in a healthy and safe manner. Failure to do so can have long term effects both on the health of your voice and your long term health as well.
Wishing you all good vocal health