Mouth sores often develop during chemotherapy because the drugs given target rapidly growing cells, which are usually associated with cancer. Unfortunately, many of these drugs cannot tell the difference between cancer cells and healthy cells. The healthy cells in your mouth and gastrointestinal (GI) tract grow very rapidly, just like cancer cells, so the drugs kill these cells too.

Because the body struggles to keep up with growing new cells, it becomes hard for your mouth and GI tract to heal. This process is what results in infections and sores. Hair cells are also fast-growing, which is why many people on chemotherapy also lose their hair.

The result of chemotherapy for many is mouth sores and sensitivity. In extreme cases, if you are not able to eat or drink, you may need to receive IV fluids and nourishment. If you do not have adequate hydration and nutrition for a period of time, this could delay cancer treatment or cause the treatment to not be as effective. So, if you notice your intake is poor and you cannot increase it, you will want to discuss this with your medical team quickly. 

Here are some tips to address mouth sores so you can keep up with your nutrition:

• Eat soft, bland foods that are cold or room temperature: This can be soothing. To continue to get nutrients, you can blend foods into smoothies, soups, shakes, or you can make mashed potatoes. You can also try ice cream, yogurt or macaroni and cheese.
• Suck on frozen fruit, ice or popsicles: Frozen blueberries, grapes and cherries are delicious and very soothing to an irritated mouth and throat. You can also try store-bought or homemade fruit juice popsicles or just plain old ice.
• Add liquids to your foods to make them easier to swallow: Add broths, sauces and gravy to make foods softer and not as rough on your mouth or throat.
• Avoid acidic foods and liquids: Avoid citrus and tomatoes as these may sting your mouth.
• Avoid hot foods and liquids: If anything is too hot, it could burn your mouth and make the pain worse.
• Avoid spicy foods: I’m sure spicy foods don’t sound good at all when you have a mouth sore but try and stay away from anything with a kick. This includes different herbs and spices that may be aggravating. 
• Try drinking through a straw: drink room-temperature or cold liquid through a straw in order to bypass the painful parts in your mouth.
• Try swishing this baking soda and salt mouth rinse. This removes food and germs, while also promoting healing: 1 quart of water, ¾ teaspoon salt, 1 teaspoon baking soda