One of the warning signs of high blood pressure is chronic headaches. This is because not enough oxygen is being able to gain access to your brain through the blood being pumped around your body. For many people, this is because their arteries and veins have become constricted and so it makes it much more difficult for the heart to pump blood around the body. Many people will experience these and dismiss them as allergies or simple sinus problems or just part of normal life. This is a big mistake. At the first sign of chronic headaches (several days straight), a person should immediately see a doctor and get his blood pressure checked. When you feel a headache, you must check your blood pressure levels. This sign is very frequent in case of high blood pressure. It is also the primary symptom felt, so it must not be ignored.