Parkinson’s disease (PD) is a neurological disease that is common in middle-aged and old-aged people. The cause of the disease is a group of nerve cells called nigrostriatal neurons, which synthesize a substance called dopamine. The cause of the disease is due to a group of nerve cells called “nigrostriatal neurons” in the brain, which synthesize a transmitting substance called “dopamine” to transmit the instructions of the brain nerves to all corners of the body, and when “nigrostriatal neurons” die by more than 80%, the synthesized “dopamine” will be reduced to the extent that it cannot transmit the signals of the brain normally. When more than 80% of the “nigrostriatal neurons” die, the synthesis of “dopamine” decreases to the extent that it cannot transmit brain signals properly, and various symptoms of Parkinson’s disease appear. In order to detect, diagnose and treat Parkinson’s disease at an early stage, we need to understand the symptoms of Parkinson’s disease, especially the early symptoms. What are the symptoms of Parkinson’s disease? There are individual differences in the first symptoms of Parkinson’s disease, which are: tremor or trembling (70.5%), muscle tone or slow movement (19.7%), dexterity and/or dysgraphia (12.6%), gait disturbance (11.5%), myalgia, spasm, pain (8.2%), psychological disorders such as depression, nervousness, etc. (4.4%), speech disorders (3.8%), generalized weakness, muscle weakness (2.7%), and generalized weakness (2.7%). (3.8%), generalized weakness, muscle weakness (2.7%), drooling and reduced facial expression (1.6% each). Patients with Parkinson’s disease may present early with decreased or loss of sense of smell, constipation, REM sleep behavior disorder, restless legs syndrome, depression, anxiety, and tremor (Wu Y, Le W, Jankovic J. Preclinical biomarkers of Parkinson disease. Arch Neurol. 2011 Jan;68(1)). (1):22-30). In general, patients with Parkinson’s disease often have resting tremor and hyperkinesia as the first symptom, such as clumsiness and resting tremor when completing fine movements such as writing, knotting shoelaces and buttons, and washing the face, especially if one side appears first or one side is heavy and the other side is light, the disease should be considered, and the disease should be suspected if it is combined with less facial expression, slow walking movements, shuffling of the lower limbs, slow and unsteady turning movements, and postural abnormalities. However, the patient’s spirit, intelligence and speech may be normal. Often, these symptoms are considered by themselves or others as a sign of aging, and the diagnosis is delayed because they are not investigated and not sought after. The main manifestation is resting tremor, which is easy to detect, while the main manifestation is tonus and decreased movement, which is often detected later. In the early stage of the onset of the above symptoms do not appear at the same time, and some of the early symptoms, even if they already exist, often do not attract the attention of patients and relatives, so it is difficult to early diagnosis. According to some statistics, the time from onset to clinical diagnosis of Parkinson’s disease is usually 2-3 years. This is often due to the patient’s easy to ignore the early symptoms and did not seek medical attention, especially in the elderly easy to be ignored. Knowing the symptoms of Parkinson’s disease, how to diagnose Parkinson’s disease? Generally speaking, the diagnosis of Parkinson’s disease is mainly based on clinical symptoms and signs, i.e. doctor’s questioning, observation and examination. Symptoms can appear and develop very slowly and in no certain order, and some tremors or movement disorders may not even be noticed until years later. Characteristics of the main signs and symptoms: 1. Tremor (shaking). Not all patients with Parkinson’s disease have tremor, but a slight or obvious tremor may occur such as the hand is rubbing the pill-like movement, usually first in one hand or hand, arm, leg. The tremor is likely to occur when the person is resting or walking, and when the person is anxious or excited. Some patients may be embarrassed by this, but a mild tremor usually does not interfere with normal motor behavior. In fact, when the hands or arms are working, the tremor is usually temporarily reduced or eliminated. About 15% of patients are always tremor-free; another 15% occur on top of simple tremor.2. Muscle stiffness. Muscle stiffness is often one of the early symptoms of Parkinson’s disease. The limbs are “lead pipe-like” or “cogwheel-like” straight; turning around, standing up from a seat, undoing buttons and other daily movements gradually become slow and increasingly difficult. Sometimes the muscle stiffness can be painful and indescribably uncomfortable. 3. Slowness of movement. Slowness of movement is another common symptom of early-stage patients. It is characterized by difficulty in starting to walk, walking becomes more and more difficult, and sometimes it is very difficult to start again once you stop walking. There is a decrease in the number of active movements and accompanying movements. 4. Postural instability. Postural instability manifests itself as an impairment of the patient’s ability to subconsciously adjust the orientation of the body and limbs. The patient may be found to have difficulty in maintaining an upright posture, bending over and touching the feet, swinging the arms during walking, and maintaining balance during collisions. There are special postures, such as forward head flexion, elbow and knee flexion, “triple flexion posture”, and so on, and it is easy to fall down when turning. 5, writing difficulties and gait disorders. Obvious tremor will affect writing, and when writing several lines in a row, the font will gradually become smaller or scribble illegible. Gait disorders may be characterized by small, choppy steps, panicky gait, forward gait, or unilateral lower extremity shuffling. There are obvious individual differences in the main symptoms mentioned above, and the main symptoms will interact with each other and lead to some other symptoms, including: reduced expression “mask face”, speech and voice abnormalities, dysphagia (salivation), constipation, sweating abnormalities, sleep disorders, fatigue easily. So is it possible to diagnose a person with Parkinson’s disease without tests? Generally speaking, typical Parkinson’s disease patients can be diagnosed after questioning by an experienced specialist. However, some atypical patients may need to undergo some auxiliary tests to rule out other concomitant diseases. For example, brain CT/MRI examination has no characteristic changes in either the early or late stages of Parkinson’s disease, and cannot provide direct diagnostic value, but can provide negative evidence. On the other hand, brain CT examination can detect the following abnormalities in patients with Parkinson’s syndrome: basal ganglia calcification, hydrocephalus, cerebral atrophy, subcortical white matter lesions, cerebral infarction, and other abnormalities. MRI examination has high discriminatory ability and is more clinically significant than brain CT for the diagnosis and differential diagnosis of this disease. Brain MRI examination can find the following abnormalities: (1) diffuse cerebral atrophy and subcortical white matter degeneration; (2) narrowing of the nigrostriatal band; (3) focal high signal in the nigrostriatum and the pallidum, which is more obvious in the weighted image, and may be due to the proliferation of glial cells; (4) focal atrophy in the nigrostriatum and the pallidum; (5) occasional iron deposition in bilateral chitin nuclei, which is characterized by a short T2 signal on the T2 weighted image, forming the “tiger’s-eye sign”, which is a rare case of the pallidum – the melanin pigmentary degeneration disease. Nigrostriatal pigmentary degeneration disease, suggesting that the patient has Parkinson’s syndrome. These can be used as differential diagnosis or as evidence to deny Parkinson’s disease. It is relevant for the diagnosis of secondary parkinsonian signs. Sometimes, routine blood tests, liver and renal function, blood glucose, lipids, and serum potassium, sodium, calcium, iron, and copper may be necessary in some patients. To date, there is no specific instrument or laboratory test that directly confirms the diagnosis of Parkinson’s disease. Therapeutic diagnosis. It is for patients who are clinically suspected of having early Parkinson’s disease, to be treated with appropriate amount of levodopa preparation, if the effect is obvious, that is, early definitive diagnosis. It is worth noting that Parkinson’s disease should be differentiated from the following diseases, such as idiopathic tremor; Parkinsonian superimposed syndromes such as multiple system atrophy (MSA-P), progressive supranuclear palsy (PSP), olivopontine cerebellar atrophy (OPCA), Lewy body disease, corticobasal ganglionic degeneration (CBD), etc.; Parkinson’s syndromes (symptomatic), such as post encephalitis, pharmacological, toxic, vasculogenic, etc. Parkinson’s syndrome, etc. The above diseases are poorly or ineffectively treated with antiparkinsonian drugs.