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People searching for cervical collar side effects are usually clinic staff, caregivers, students or buyers who want to know what problems are reported with collar wear and how strong the evidence is. The short answer: the most consistently reported problem is pressure ulceration, with swallowing difficulty and raised intracranial pressure also reported, but the studies are mostly low quality and none establishes a safe wear time.
What is a cervical collar, and who uses it?
A cervical collar is a neck orthosis worn to limit movement of the cervical spine. Clinicians, emergency and trauma teams, rehabilitation staff and patients use soft and rigid designs; see what a cervical collar is, soft collars, Aspen collars and Philadelphia collars. The evidence below mostly concerns rigid (“hard”) collars worn in hospital after trauma.
What side effects are reported with cervical collar use?
A 2022 systematic review and meta-analysis in Global Spine Journal (Brannigan et al.) examined adverse events linked to prolonged hard collar immobilisation, defined as two or more days of wear. It included 25 studies and concluded that the most commonly reported complications were pressure ulcers, dysphagia (swallowing difficulty) and increased intracranial pressure. Only pressure ulceration had enough data for a pooled estimate.
| Reported effect | Figure reported | Strength of evidence | Source |
|---|---|---|---|
| Pressure ulceration | Pooled prevalence 7% (95% CI 4-13%), 8 studies; heterogeneity high (I² 78%) | Pooled, but low-quality, inconsistent studies | Brannigan 2022 |
| Dysphagia | Moran 2013: 50% with no control group; Kalb 2012: no significant association with collar use; Borders 2018: bracing a significant predictor of dysphagia and its severity | 3 studies, no pooled estimate, conflicting | Brannigan 2022 |
| Raised intracranial pressure | Increases in optic nerve sheath diameter on each of 5 days in healthy volunteers (one randomised trial) | Single trial, indirect measure, not patients | Brannigan 2022 |
| Skin erythema | 10 of 51 (20%), Hylton | Single study | Brannigan 2022 |
| Mood swings or low self-esteem | 6 of 51 (12%), Hylton | Single study | Brannigan 2022 |
| Delirium, lower respiratory tract infection, falls | 3 of 8 (38%), 5 of 8 (63%), 3 of 8 (38%), Moran | One small study | Brannigan 2022 |
| Reduced cervical range of motion | Larger after 8 than 4 weeks of wear | One retrospective study | Brannigan 2022 |
The review’s own conclusion: “There is significant morbidity from prolonged hard collar immobilisation, even amongst younger patients.” Its authors note that nerve compression palsies were mentioned in their conclusion but not analysed.
How common are pressure ulcers with a cervical collar?
The pooled prevalence in the meta-analysis was 7% (95% CI 4-13%). Individual studies ranged widely, and the review found that age and duration of immobilisation were not significantly correlated with ulceration in its analysis. A 2013 systematic review in the Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine (Sparke, Voss and Benger) states there are numerous accounts of skin ulceration associated with cervical collars, and describes ulcers over the occiput (back of the head) as the most severe because there is little subcutaneous tissue over the bone. For the wider topic, see pressure injury prevention programmes.
Can a cervical collar cause swallowing problems?
The evidence conflicts. Of three studies reviewed by Brannigan et al., one reported dysphagia in 50% of patients without a control group, one found no significant association between collar use and dysphagia, and one found bracing to be a significant predictor of dysphagia and its severity. The Sparke review does not address swallowing. Treat the link as possible but unsettled.
Does a cervical collar raise intracranial pressure?
Possibly, but the evidence is indirect. The one randomised trial in the Brannigan review studied healthy volunteers over five days and measured optic nerve sheath diameter as a proxy for pressure; increases were seen each day. Sparke et al. link reported rises to external compression of the jugular veins, but state this is not proven as the cause. A volunteer study (Stone 2010, n=42) found collar application altered jugular vein diameter in a way indicative of venous obstruction, without showing a causal link to intracranial pressure. The same review notes that discomfort or pain may also matter, and that semi-rigid collars impede effective airway management.
Why do these effects happen?
- Sustained pressure over bony areas. The occiput and other contact points have little padding. Sparke et al. relate tissue interface pressure to capillary closing pressure.
- Neck compression. External pressure on the neck is the proposed (unproven) route to venous obstruction and raised intracranial pressure.
- Restricted movement. Immobility is the intended effect, and prolonged restriction is associated in one study with reduced range of motion.
Prolonged use versus short use
The Brannigan review covers wear of two days or more, mostly in trauma inpatients, not brief emergency immobilisation. These findings should not be read as describing short-term use. Equally, the evidence gives no safe wear duration: how long a collar stays on is a decision for the treating clinician following the manufacturer’s instructions for use. Wear-time questions are also touched on in the cervical collar types and sizing guide.
Common misunderstandings
- Treating the 7% as a per-patient risk. It is a pooled figure from heterogeneous, low-quality studies and ulcer identification was inconsistent.
- Assuming the absence of a figure means the absence of harm. The review states complications are likely underreported.
- Quoting single-study percentages as general rates. Figures such as 63% for respiratory infection come from one study of 8 patients.
Limits of the evidence
Brannigan et al. report inconsistent methods and outcome measures, low-quality evidence, mostly trauma inpatients, and call for high-quality prospective studies. Sparke et al. note small, retrospective, single-centre studies and no formal risk-of-bias assessment.
FAQ
What are the side effects of a cervical collar?
Pressure ulcers, swallowing difficulty and increased intracranial pressure are the most commonly reported with prolonged hard collar use; other effects appear in single studies (see the table).
How long can you wear a cervical collar?
The reviewed evidence does not identify a safe duration. Follow the treating clinician and the manufacturer’s instructions for use.
Where do collar pressure ulcers occur?
Ulcers over the occiput are described as the most severe, because little soft tissue lies over the bone.
Sources
- Brannigan JFM, Dohle E, Critchley GR, Trivedi R, Laing RJ, Davies BM. Adverse Events Relating to Prolonged Hard Collar Immobilisation: A Systematic Review and Meta-Analysis. Global Spine Journal 2022;12(8):1968-1978. https://pmc.ncbi.nlm.nih.gov/articles/PMC9609519 (date checked 2026-10-30)
- Sparke A, Voss S, Benger J. The measurement of tissue interface pressures and changes in jugular venous parameters associated with cervical immobilisation devices: a systematic review. Scand J Trauma Resusc Emerg Med 2013;21:81. https://pmc.ncbi.nlm.nih.gov/articles/PMC4222127 (date checked 2026-10-30)
