“Ask Dr. HKSH” - What are the red flags for acute severe headaches?


Q1. I have frequent headaches. Is there anything wrong with my brain?
Headaches are very common. Do frequent headaches have to do with brain problems? Not necessarily. In fact, there are over 100 causes of headaches, and only a few have to do with brain problems. Despite this, you still need to beware of any warning signs and consult doctor when necessary. 

Q2. What warning signs should I look out for?
What are the red flags for life-threatening headaches? If they are not dealt with timely and effectively, will it delay diagnosis?  Under this circumstance, one should take note of the headache’s characteristics, one’s own medical history and the occurrence of accompanying symptoms. Firstly, a headache is considered dangerous if it occurs suddenly and the pain level becomes unbearable in less than a minute, just like thunder or explosion.  This is called a thunderclap headache, and must not be ignored. Beware of any difference from previous headaches in terms of features, severity, feeling, etc.

Secondly, one’s medical history should be considered, especially if one is over 50 years old and has injured in a fall incident, a few days or even 1 or 2 months earlier. Those who have had cancer, suffer from immune system diseases or are taking blood thinners or anti-platelet medications should also pay extra attention when headaches occur.

Thirdly, be wary if the headache comes with other symptoms as well, e.g. headaches with epileptic seizure, fever, disorientation, dizziness, a wobbly gait, limb weakness, loss of vision, double vision or hearing impairment. Always consult your doctor if you are unsure about the symptoms. There is no need for undue concern over mere isolated headache that are without accompanying symptoms.

Q3. What should be done if there is more than one warning sign?
A headache can be dangerous if it strikes like thunder and causes unbearable pain within a minute. In this case you should seek immediate medical attention or visit the nearest A&E. If the headache comes on slowly but gradually gets worse, and you have a medical history of, among others, lung cancer, breast cancer, etc., please also seek consultation as soon as possible.  Medical attention is also required if you are not sure about nature of the headache and the warning signs. 

Q4. What conditions are associated with dangerous headaches?
There are 3 types of dangerous headaches, i.e. those that are associated with vascular diseases, brain tumours and inflammation. Common cerebrovascular diseases include a ruptured aneurysm or major cerebral artery dissection, ruptured brain arteriovenous malformation, and cerebral venous thrombosis, which can be dangerous by causing severe bleeding. The second type has to do with brain tumours, mostly the malignant ones. Due to their aggressive nature, primary malignant tumours such as like glioblastoma or metastasis may grow rapidly and give rise to symptoms. The third type is associated with brain inflammation, e.g. meningitis, encephalitis and giant cell arteritis. All of them can lead to severe headaches. Headaches are usually caused by high brain pressure, however there is a rare type of headache caused by excessively low brain pressure.. Specialists can distinguish this condition which requires special workup. 

Q5. Can early examination prevent the above mentioned diseases? 
It is still controversial whether individuals with no symptoms should be put to large-scale screening. However, people with mild symptoms should undergo examination early, including those who are aged over 50, have mildly injured in fall incidents, are on blood thinners, have a higher risk of cerebral haemorrhage, have concurrent cancer treatment (or past history of cancer that make them at a higher risk of brain metastasis).

The warning signs are for reference only. You should consult your doctor for a thorough discussion of your medical history, followed by a detailed physical check-up for a personalized follow-up plan. A brain scan, i.e. CT or MRI, may be necessary, and is arranged only after a detailed discussion with your doctor.

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