There were many kinds of illnesses in novels. Some described the discomfort of the character's body, while others described the pain in the character's heart. Below are some common novel symptoms: Headache: It can be a mild headache or a severe headache. Cough: It can be a slight dry cough or a serious cough. Stomachache: It can be a mild stomachache or a serious stomach sore or inflammation. Diarrhoea: It can be mild diarrhea or severe diarrhea and constipation. 5. Ininsomnia: It can be long-term insomnia or mild insomnia. 6. Heart palpitations: It can be mild or severe. 7. Exhaustion: It can be mild fatigue or severe fatigue. 8. Mental Disorders: For example, depression, anxiety, etc. 9. Muscle pain: For example, muscle soreness, muscle wasting, etc. 10 Skin disease: For example, skin allergy, skin disease, etc. These were just some of the common symptoms in novels. The specific symptoms needed to be determined according to the plot of the novel and the setting of the characters.