Medical Lore for the setting.

There are four types of Qi which are linked to bodily functions, emotions, and health. Each type corresponds to specific Meridians in the body, which are channels through which Qi flows.  

Sanguine Qi: Heart Meridian, Pericardium Meridian, Triple Burner Meridian
    Associated with blood circulation and healing. A balanced Sanguine Qi can result in good circulation, a strong immune system, and a positive outlook on life. However, an imbalance of Sanguine Qi can lead to anxiety, restlessness, and a tendency to become easily overexcited. Physical symptoms of an imbalance in Sanguine Qi can include heart pain, dizziness, speech impediments, and insomnia.

Phlegmatic Qi: Lung Meridian, Bladder Meridian, Kidney Meridian
    Associated with fluid metabolism and respiratory health. A balanced Phlegmatic Qi can result in a strong respiratory system and a sense of inner peace. However, an imbalance of Phlegmatic Qi can lead to a lack of motivation, apathy, and a tendency to become overly lethargic. Physical symptoms of an imbalance in Phlegmatic Qi can include coughing, congestion, headache and bloating

Choleric Qi: Stomach Meridian, Gallbladder Meridian, Liver Meridian
    Associated with digestion and metabolism. A balanced Choleric Qi can result in strong digestion, efficient metabolism, and a confident, decisive personality. However, an imbalance in Choleric Qi can lead to anger, frustration, and a tendency to become overly aggressive or irritable. Physical symptoms of an imbalance in Choleric Qi can include acid reflux, indigestion, and high blood pressure.

Melancholic Qi: Large Intestine Meridian,  Small Intestine Meridian, and Spleen Meridian
    Associated with nutrient absorption and elimination. A balanced Melancholic Qi can result in good digestion, healthy waste elimination, and a focused, introspective personality. However, an imbalance in Melancholic Qi can lead to depression, pessimism and a tendency to become overly self-critical. Physical symptoms of an imbalance in Melancholic Qi can include constipation, diarrhoea, and digestive issues related to stress.

All of the Meridians are especially tightly pack slightly bellow the navel in a location called the Dantian. Martial artist can cultivate their Dantian to allow them to utilise their Qi to perform extraordinary feats.

Mushi are beings that are generated by miasma, noxious foul smelling fumes that can arise from various sources such as stagnant water, decaying organic matter, and pollution. Miasma is thought to disrupt the flow of Qi in the body, which can lead to physical and emotional symptoms and even illness. Mushi interact with the body in complex ways and are the cause of pathogenic diseases.

Some example diseases are listed bellow.

Carbuncle:
Is a grave illness that is believed to stem from an imbalance in Sanguine Qi, resulting in the formation of crystalline stones from the blood that break through the skin. This disease causes excruciating pain, organ damage, and heart failure if left unattended.
Carbuncle appears as areas of the skin that are inflamed, painful, and swollen, and are accompanied by numerous openings through which the red, gem-like stones emerge. These stones come in varying sizes and can cause significant discomfort to the afflicted.

Cinderella:
Is an infectious disease that causes the skin on the feet to vitrify into a hard and brittle glass-like material. It is common in areas where witches and heretics are burned at the stake. If left untreated, it can spread to other areas of the body and cause additional health complications. Treatment involves softening the vitrified skin with salves or ointments, and in severe cases, surgical removal.

The Red Death:
Is a highly contagious disease that has ravaged communities. This disease is characterised by initial symptoms of rashes and fever, which progress to severe internal bleeding and the sweating of blood. Red Death is a lethal disease, and victims rarely recover once infected.
The disease is believed to be caused by contact with tainted blood, and once infected, the disease spreads rapidly through the bloodstream. The symptoms of Red Death are severe, causing great pain and suffering for those affected.

Moskrema:
Is a disease that appears to be caused by frequent exposure to putrid water. The disease affects those who come into contact with contaminated water and is characterized by joint aches, muscle weakness, and numbness, leading to a loss of sensation in the affected areas. The aching pains caused by the disease can be temporarily relieved by immersing oneself in water. However, the reluctance to leave the water can cause the skin to become soft, wrinkled, and prone to gangrene.