After treatment to the head and neck area, the first thing most people notice is what's going on inside their mouth. When saliva drops off, it's not just a matter of feeling thirsty. Talking and swallowing both become oddly uncomfortable. You end up chasing every spoonful of food with a few sips of water, and you wake up in the night with your mouth dry as a desert. When the salivary glands take a hit from radiation, it's not only that you make less saliva. What's left turns thick and sticky, and its whole character changes. So this isn't something you can brush off with "just drink a little more water." You have to run your whole day a little differently.
The most practical move is to keep a water bottle within arm's reach at all times. Rather than gulping it all down at once, sipping a little and often keeps your mouth comfortable for longer. Stash a small bottle by the front door, at your bedside, in front of the TV, and your hand will reach for it without you even thinking about it. Go for foods with some broth or liquid, and for dry things like bread or sweet potato, dunk them in sauce or soup. Keeping a piece of sugar-free gum or candy in your mouth stimulates the salivary glands and gets at least a little saliva flowing. The key word here is "sugar-free." When your mouth is dry and you add sugar to the mix, tooth decay sets in with frightening speed.
Nighttime is the hardest stretch. People who sleep with their mouth open wake up even drier, so running a humidifier to bring the room's humidity up makes a real difference. Moisturizing products you dab on or hold in your mouth before bed, and artificial saliva (인공 타액) from the pharmacy, can also help. The right form differs from person to person. Some people find a gel comfortable, others do better with a spray, so it's worth trying a few and finding what suits your own mouth.
One thing that's surprisingly easy to overlook is keeping your mouth clean. With less saliva, the natural self-cleaning action that rinses out your mouth weakens, so cavities and gum disease come on much faster. Brush gently with a soft toothbrush, and steer clear of alcohol-based mouthwashes, since they actually dry your mouth out more. Protect your teeth with fluoride products, and be more diligent than usual about regular dental check-ups. Once your teeth start to break down during this period, it's much harder to recover.
And the things that dry your mouth out further, keep your distance from them where you can. Alcohol, tobacco, caffeine-heavy coffee, and salty or spicy food all irritate an already dry mouth. The truth is these are usually all the things you used to enjoy, so they're not easy to give up. But cutting back even for a while makes a fairly big difference in how your mouth feels. Once you actually try it, it's bearable, and your body feels lighter for it too.
Dry mouth sometimes eases off bit by bit as time passes, and in other cases it settles at a certain level. If it lingers too long and too severely, or comes with pain or sores inside your mouth, don't just grit your teeth through it. Tell your care team, and there are treatments they can prescribe to help. What's written here is simply about the everyday management you can try yourself, so for what's right in your own situation, please be sure to talk it over with your own medical team.