The diabetic foot is a combination of diabetic neuropathy and/or vascular disease and infection that causes damage to the foot in diabetic patients. Why is the diabetic foot so difficult to treat? First of all, the first complication that usually occurs in diabetic patients is peripheral neuropathy, for example, the patient feels numbness, ankylosis, insect crawling, heat, electric shock-like sensation in the lower limbs, often from the distal toes up to the knee, and the patient has a sock and glove-like sensation. That suggests that there are already early symptoms of peripheral neuropathy. As the disease progresses, the patient has motor nerve, sensory nerve and autonomic nerve damage, and the foot is vulnerable to injury once it loses the protective effect of the nerve, or the damage is already there, but the patient does not feel it until it is very serious. It can be said that almost every patient with diabetic foot has diabetic peripheral neuropathy. Due to the damage of the motor nerve in the foot of diabetic patients, the imbalance between the extensor and flexor muscles of the foot cannot maintain the normal posture of the foot, which often causes the unevenness of the bottom of the foot, the local subsidence of the bottom of the foot (plantar fat pad and metatarsal head), and even the formation of “bowed foot” or “chicken claw toe “deformity. With the extension of time, the foot muscles atrophy, the normal posture and elasticity of the foot is lost, and the plantar area (metatarsal) endures heavier pressure when walking, and the weight-bearing is on a smaller area, which is poorly protected by the soft cushion, so it is easily damaged and leads to breakage. After injury to the autonomic nerve of the lower extremity, the skin of the extremity has little or no sweating, and the skin of the patient’s foot is dry and cracked, which is susceptible to bacterial infection causing ulcers, cellulitis, and deep abscesses. In addition, the autonomic nerve can control the micro blood flow of the skin, when the autonomic nerve is injured, resulting in increased blood flow to the skin especially in the hypochondrium, which can lead to edema or atrophy of the skin of the lower extremity, and ulceration can occur. Sensory abnormalities mainly include numbness, pain, burning or radiating pain in the tissues, and impaired or absent sensation in the foot, often leading to penetrating neuropathic ulcers. The foot sensation is dull and often painless after trauma, and the patient is unaware of the injury or has known the injury but is negligent without painful suffering and is infected by bacteria to develop severe extremity ulceration. Second, diabetic peripheral vasculopathy makes it difficult to heal minor injuries in diabetic patients. Diabetic peripheral vasculopathy mainly involves the arteries of the lower limbs, especially the N artery below the knee, the posterior tibial artery and the peroneal artery, etc. These atherosclerotic plaques and thrombosis of the arteries cause luminal narrowing and occlusion, resulting in distal limb ischemia, which prevents the tissues from obtaining sufficient oxygen and nutrients and from discharging metabolic waste in a timely manner and prevents therapeutic drugs from reaching the lesion site effectively. Intermittent claudication is the early manifestation of lower limb ischemia. Due to insufficient blood supply to the muscles caused by lower limb ischemia, the lower limbs become weak, tired and numb after walking for a period of time, and in severe cases, the calf gastrocnemius muscle is painful, and the symptoms can be relieved after stopping walking and resting. Resting pain is a manifestation of the middle stage of the lesion, when the lesion develops and the ischemia of the lower limb is serious, pain occurs even without walking, this pain is mostly limited to the toes and toe ends, especially at night, and the pain increases when lying down, and can be relieved by dropping the lower limb. Later in the disease, gangrene of the toe ulcers: dry skin, keratinization, muscle atrophy, dorsal bending deformity of the toes, and blisters appear after friction. When the blisters break, bacterial invasion and infection occurs, resulting in cellulitis and chronic ulcers, which are difficult to heal over time. Finally, infection is a major threat to the diabetic foot, and infection and multiple drug resistance can affect the extent of ulceration, outcome, and prognosis. There are many causes of foot infections in diabetic patients, both foot and systemic factors. For example, skin damage, high-risk foot, foreign body retention in the wound, dead space, and poor drainage. Systemic factors, often related to metabolic disorders, vascular and neurological lesions, malnutrition, decreased immune function and resistance of the body, etc. There are conditions suitable for bacterial growth and reproduction throughout the body or locally for bacteria to survive. Due to the toxic products produced by bacterial toxins or their destroyed necrotic tissues, a series of local or systemic changes can be caused, making the diabetic foot difficult to cure, and some even lose their lives in this way. Diabetic foot is difficult to treat because of diabetic neuropathy, diabetic vasculopathy, infection, while diabetic patients often have metabolic disorders, malnutrition, decreased immune function and resistance, etc. The combined effect of these factors is that the diabetic foot is not easy to heal. To put it in layman’s terms, just like farmers planting, a good harvest requires a variety of factors. The land should have the environment for seeds to germinate and grow, rain and nutrients should be sufficient, the temperature and sunlight should be appropriate, and natural disasters should be prevented. Without sufficient rain and nutrients, even if the seeds germinate, they will not thrive, which is obvious, and diabetic foot patients with peripheral vascular disease do not have sufficient blood supply to their feet, just as bad as the seeds without sufficient rain and nutrients. Moist soil and suitable temperature and sunlight are the prerequisites for seeds to germinate and grow, without which it is difficult for seeds to germinate and grow, while our peripheral nerves sense pain and warmth, regulate micro blood flow in the skin, and constantly adjust the muscles and bones of the foot to keep the foot in balance from damage. Even if the crops are growing well and are about to be harvested, once they are hit by heavy storms, especially hail, or serious insect infestation, farmers will suffer and even lose the harvest, which is as deadly as a diabetic foot infection. This is the reason why diabetic foot is difficult to treat. But difficult to treat does not mean that it cannot be cured.