Pain is the most common and important sign and symptom in clinic, and it is always accompanied by negative emotions. Therefore, the care of pain is very important. Pain is a complex feeling and a signal that harmful factors invade the body, which is often closely related to the occurrence, development and prognosis of diseases. Pain is one of the important indications of disease diagnosis and differentiation, and it is also the standard to evaluate the effect of treatment and nursing.

In psychosomatic medicine, the threshold is defined as the level at which 50% stimulation can be recognized. According to this definition, the pain threshold should be the level at which 50% of stimuli are perceived as pain. If this stimulus is not felt, the pain threshold cannot be used as a measure of pain. 1, visual analogue scale (VAS).

2. Speech Description Scale (VDS).

3. Digital Rating Scale (NRS)

According to the patient's self-evaluation on 10 scale, the pain was 0, 1 ~ 3 was mild, 4 ~ 6 was moderate, and 7 ~ 10 was severe.

4.Wong-baker Facial Expression Pain Scale

By observing the patient's behavior changes, six different facial expressions (from smile to sadness to crying) are used to express the degree of pain. From left to right, it is marked as 0 ~ 5 points, indicating no pain, very slight pain, slightly significant pain, severe pain and severe pain. Because it is intuitive and easy to understand, it is more suitable for patients with serious illness, difficulty in publishing papers and language expression.

5. McGill's pain rating

The pain was divided into five grades by question and answer method. Master thesis similarity test: level 0 does not hurt; 1 grade pain but not serious; Grade 2 mild pain, uncomfortable; Grade 3 pain, pain; Grade 4 pain is more intense, fear; Grade 5 pain.

6. According to the WHO pain grading standard, pain is divided into four grades:

Grade 0: painless.

1 grade (mild pain): no pain when lying flat, mild pain when coughing when turning over, but tolerable, and sleep is not affected.

Grade 2 (moderate pain): pain when lying flat, aggravated when coughing when turning over, unbearable, disturbed sleep, and need analgesic drugs.

Grade 3 (severe pain): when lying still, the pain is severe and unbearable, and the sleep is seriously disturbed, requiring analgesic drugs.

6. Prince-Henry scoring method:

0: It doesn't hurt when coughing.

1: Pain when coughing.

2 points: there is no pain when you are quiet, and there is pain when you take a deep breath.

3 points: There is pain at rest, but it is mild and tolerable.

4 points: There is severe pain at rest, which is unbearable.