1. You can see clearly without reading glasses. Not real vision improvement, but cataract. The human eye is very much like a camera, and the lens is the lens in the camera, just like a transparent convex lens. The light projected to the eyes by external objects can only be projected to the retina behind the eyeball after the focal length is adjusted by the lens, and the objects in front of us can be seen clearly. The reason why middle-aged and elderly people need reading glasses is that their lenses are becoming "hard" and their adjustment function is declining, which is completely a physiological transformation phenomenon. Once you have a cataract, your early vision is not seriously damaged, but the lens swells and thickens because of absorbing water, which plays the role of reading glasses. This is why you can see clearly when you take off your reading glasses at this time, but this is not a visual improvement. When the cataract continues to develop, your vision will be severely impaired.
2. White hair turns black. This is good news that people can easily render as "rejuvenation". In fact, gray hair of the elderly is a natural phenomenon, but suddenly turning from white to black is not a good thing, which is often a dangerous signal of pituitary adenoma or adrenal cancer. If the skin becomes tender and sexual desire increases at the same time, you should be more vigilant.
3. Tooth regeneration. Due to the atrophy of periodontal tissue, the support of the elderly is weakened, and there are many different degrees of dental diseases, and tooth loss is inevitable. If a tooth falls out, it won't regenerate itself. Then why do some old people grow "new teeth"? In fact, after the teeth fall off, the residual teeth or roots in the original gums are exposed, and no new teeth really grow. On the contrary, if a complete new tooth really grows in the mouth, we should be alert to whether it is a signal of endocrine diseases or some tumors, and we should not be careless.
4. Vaginal bleeding of menopausal women. This phenomenon is usually called "upside down" by ordinary people. Under normal circumstances, menopausal women cannot produce mature eggs due to the decline of ovarian function, and menstruation is terminated. If there is a sudden "upside down" phenomenon, it is not a "double split", but often a signal of cervical cancer, uterine tumor or ovarian tumor. You should go to the hospital for examination at once. Of course, a few women who are using estrogen replacement therapy may bleed, but this kind of bleeding is a normal reaction, so you can ask a doctor to identify it and eliminate concerns.