If an older person, two or three weeks to a few months after bumping their head, becomes unsteady on their feet, slow, sleepy or weak on one side, get a head CT

In a real emergency, call 911 first, then read this.

Cost

A head CT costs two or three hundred CNY.

What you get

The Chinese Medical Association's neurosurgery branch and others published the Chinese Expert Consensus on Drug Treatment of Chronic Subdural Hematoma (《慢性硬膜下血肿药物治疗中国专家共识》). A chronic subdural hematoma is a pool of blood that slowly collects between the membranes around the brain. Professionally it is described as a chronic space-occupying collection of blood between the arachnoid and the dura. It "usually forms in the third week after a head injury" and is more common in older people. After surgery the recurrence rate can reach 33% and the death rate 32%. For patients over 90, only 24% recover well overall. A systematic review: worldwide there are 3.39 to 39.1 new cases per 100,000 (10万) people per year, rising with age, and up to three times higher over 80. The most common causes are injury and falls, followed by long-term heavy drinking, medicines that stop blood clotting (anticoagulants) and violent injury. A geriatric medicine review: the presentation "typically includes confusion, cognitive decline, gait disturbance or sleepiness, and may resemble other geriatric syndromes." The same review also says the rising number of cases is linked to more people taking anticoagulants and antiplatelet drugs (such as aspirin and clopidogrel), and older people falling more easily. Another literature review states that there is a gap between the injury and the symptoms, and the injury is usually very mild, so it is often overlooked. More than 50% of patients deny any injury

Notes

At the time of the knock it is often only a minor bump, and more than half of these older people can't say they were injured. So when the family finds "suddenly confused lately, floating when walking, always sleepy, one hand weak," first go back and ask whether they fell or hit their head in the last two or three months, and then get a CT. Its presentation looks like other illnesses of old age; don't put it straight down to "dementia" or "after-effects of the last stroke." Older people taking aspirin, clopidogrel, warfarin or the newer oral anticoagulants are at higher risk, and so are people who drink heavily over a long time. For preventing falls, see §1.13 (train balance and leg strength). For memory that gets worse year by year without a bump to the head, see §17.13 (memory clinic).

Evidence grade

B : Supported by research but without a precise number, or based on small or single studies.

Sources

1. Zhang J et al. (2021). Expert consensus on drug treatment of chronic subdural hematoma. Chinese Neurosurgical Journal, 7(1), 47. https://doi.org/10.1186/s41016-021-00263-z
2. Dziho A et al. (2025). Global prevalence and incidence of chronic subdural hematoma: A systematic review. Brain and Spine, 5, 105893. https://doi.org/10.1016/j.bas.2025.105893
3. Mathon B, Shotar E (2026). Diagnostic and therapeutic management of chronic subdural hematoma in elderly patients. Gériatrie et Psychologie Neuropsychiatrie du Vieillissement, 24(1), 30-41. https://doi.org/10.1684/pnv.2026.1274
4. Iliescu IA, Constantinescu AI (2015). Clinical evolutional aspects of chronic subdural haematomas - literature review. Journal of Medicine and Life, 8(Spec Issue), 26-33: "the brain injury, usually minor" "patients deny the existence of a trauma in over 50% of the cases". https://europepmc.org/article/MED/26361507

Translated from the Chinese original. Original book, section 13, tip 10. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer