Upper pressure 135 lower pressure 105 that is, high pressure 135 low pressure 105, the normal blood pressure range is lower than 140 / 90, if not the same day three measurements are still the value of the level, low pressure 105 is higher than the normal range, whether there is a danger, depending on the individual situation and whether accompanied by other diseases. 1. Not too dangerous: Although the low pressure 105 is higher than the normal range, but if it is only once in a while, it is usually not a big problem, may be due to overwork and other problems, after resting can be relieved, there is no danger. 2. Dangerous: If low pressure 105 is accompanied by symptoms such as dizziness and headache or no symptoms, but itself has diabetes, coronary heart disease, cerebrovascular disease and other underlying diseases, it may cause cardiovascular and cerebrovascular danger. Nothing is absolute, so when you have a high pressure 135 low pressure 105, you must pay attention to it and seek medical attention in time so as not to miss the condition.