Common, mostly mild, and usually gone within a day or twoStrong evidence
Studies in different countries agree. In 529 patients treated for neck pain by 79 Dutch chiropractors, 56% reported a new or worse symptom after one of their first three visits, mostly pain or stiffness, and 13% rated it severe, but "No serious adverse events were recorded during the study period". In a US trial of 336 people with neck pain, "Increased neck pain or stiffness was the most common symptom, reported by 25% of the participants". Over up to six visits, 55% of 1,058 new Norwegian chiropractic patients had a reaction, mostly local discomfort, mild or moderate in 85% of patients; 60.9% of 465 Belgian patients had one after a first visit to a manipulative therapist; and 31.0% of 1,090 patients of chiropractors using upper neck techniques had one within 24 hours, intense in 5.1%. A review of manual therapy by regulated therapists found minor or moderate short-lived reactions in about 41% of patients in cohort studies and 22% in trials.
"Sixty-four percent of reactions appeared within 4 hours of treatment, and 74% had disappeared within 24 hours", and Swedish patients' reactions were "usually gone the day after treatment". The US National Center for Complementary and Integrative Health (NCCIH) says "Most of these side effects go away within 24 hours", the General Osteopathic Council (GOsC) tells osteopathy patients "it is not unusual to sometimes feel sore in the first 24 to 48 hours after treatment", and the GCC says "Some patients also report temporary aches and pains during and after treatment".
Sources 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Part of it is the neck pain you went in withEmerging evidence
Many people see a chiropractor for neck pain that comes and goes, and some soreness afterwards is its ordinary course. In a blinded trial of 183 adults with spinal pain, "Thirty-three percent of the sham group and 42% of the usual care group reported at least 1 adverse event", and the authors concluded "A substantial proportion of adverse events after chiropractic treatment may result from natural history variation and nonspecific effects". In a trial of 767 people with neck or back pain, "Excluding spinal manipulation or stretching do not affect the occurrence of adverse events", and a meta-analysis of 14 trials found that the quick thrust of neck manipulation gave no more mild or moderate side effects than the comparison treatments.
"Reactions are most commonly reported by women and (for both genders) at the beginning of the treatment series". In the Dutch neck study, a technique that rotates the neck, and being off sick or on workers' compensation, went with more reactions, and longer neck pain in the past year went with a headache or worse neck pain after the first visit. The Royal College of Chiropractors says "Sometimes, if you have had a problem for some time, you may experience post-treatment soreness in the early stages of your treatment plan". In the US trial, reactions were somewhat likelier after manipulation than after gentler mobilisation, though the difference could have been chance. In older adults, soreness and stiffness are common, and "No catastrophic AEs were reported in older adults receiving chiropractic treatment services" in the studies reviewed (AEs are adverse events).
Sources 11, 12, 13, 7, 14, 15, 2, 16
Headaches, dizziness, tingling and the throatEmerging evidence
A headache made up 12% of reactions in the Norwegian study, 19.8% of Belgian patients reported one, and upper neck manipulation went with more headaches. In a UK survey of 50,276 neck manipulations, a headache within 7 days followed at most about 4 in 100 consultations, and "There were no reports of serious adverse events". Most fit a tension-type headache or a headache from the neck, as our tension headache and neck headache guides describe; a sudden, severe headache is different, and the warning signs cover it.
In the same survey, "The highest risk immediately after treatment was fainting/dizziness/light-headedness in, at worse approximately 16 per 1000 treatment consultations". Dizziness and nausea were each 5% or less of reactions in the Norwegian study, and tiredness, dizziness, nausea or ringing in the ears affected under 8% of the Dutch neck patients. The survey counted how often, not how long, so our view that a moment of light-headedness passing within minutes is the usual pattern is our suggestion. Numbness or tingling in the arms within 7 days followed at most about 15 in 1,000 consultations, and in the US trial, people with more neck disability at the start had more nerve-type symptoms afterwards.
"Throat pain after chiropractic adjustment" is a common search. No study counts it; tender muscles at the front of the neck after pressure or a stretch are the likeliest reason (our reading). Trouble swallowing needs help straight away, and a lump, a hoarse voice or difficulty swallowing that isn't getting better needs a GP.
Sources 3, 4, 17, 1, 2
Rarely, a torn neck artery: what the studies show, and what they can'tMixed evidence
A tear in a neck artery (cervical artery dissection) is rare in anyone, and it can begin with neck pain and headache before any stroke: the American Heart Association says "Patients with CD may present with unilateral headaches, posterior cervical pain, or cerebral or retinal ischemia" (CD is cervical artery dissection). That is why a link with chiropractic care is hard to read: a tear already under way can send someone to a chiropractor, or a GP, for neck pain and headache.
In Ontario, people under 45 with this kind of stroke were about five times as likely to have visited a chiropractor in the week before. A larger Ontario study found "In those aged <45 years, cases were about three times more likely to see a chiropractor or a PCP before their stroke than controls" (a PCP is a GP), concluded the link "is likely due to patients with headache and neck pain from VBA dissection seeking care before their stroke", and "found no evidence of excess risk of VBA stroke associated chiropractic care compared to primary care" (VBA means the arteries at the back of the neck); an erratum to that study was published in 2010, which we couldn't read. Later studies agree: no link in 1,829 US cases, no excess risk of carotid stroke, none in older adults on Medicare, and, in 431,492 matched pairs of adults with new neck pain or headache, "31 SMT (0.007%) and 58 ibuprofen (0.013%) recipients had new CeAD during the 30-day follow-up" (SMT is spinal manipulation, CeAD a neck artery tear).
One US case-control study disagrees: in 51 people with a tear and 100 controls, manipulation in the previous 30 days was more common in those with a vertebral artery tear, even after allowing for neck pain. A meta-analysis rated all this evidence very low quality and concluded "There is no convincing evidence to support a causal link between chiropractic manipulation and CAD" (CAD is a neck artery tear). The American Heart Association says "It is unclear whether this is due to lack of recognition of preexisting CD in these patients or due to trauma caused by CMT" (CMT is neck manipulation), and that "patients should be informed of the statistical association between CD and CMT prior to undergoing manipulation of the cervical spine"; a correction to its statement was published in 2016, which we couldn't read. A Royal College of Chiropractors review agrees the association in under-45s exists but "it is unclear whether this is causal". These are observational studies: none can show that neck manipulation caused a stroke, and none can rule it out.
Sources 18, 19, 20, 21, 22, 23, 24, 25, 26, 27
How rare, who is at risk, and what the case reports showEmerging evidence
Neck artery tears are uncommon, about 3 per 100,000 people a year for the carotid and 1 per 100,000 for the vertebral artery, as one study summarises. Estimates of serious events after spinal manipulation range "from 1 per 2 million manipulations to 13 per 10,000 patients"; an overview of 118 reviews found estimates "roughly ranging from 1 in 20,000 to 1 in 250,000,000 manipulations" and concluded that "the types of SAEs reported can indeed be significant, sustaining that some risk is present" (SAEs are serious adverse events); and the NCCIH says serious problems "are very rare, and there are no accurate estimates of how often they occur".
Risk factors for a tear in anyone include migraine, recent infection, minor trauma and high blood pressure: "Genetic factors, cardiovascular risk factors, recent infection and minor trauma are risk factors for CAD". The NCCIH adds that "Any kind of sudden neck movement, such as those involved in playing sports, getting whiplash, and violent vomiting or coughing, may also increase the risk of tears". In 227 published cases of a serious event after neck treatment, "Manipulation was reported in 95% of the cases", and "Pre-manipulative cervical instability and arterial integrity tests appear to be unreliable in identifying patients at risk for adverse events" (a corrigendum to this review was published, which we couldn't read). A review of 134 case reports judged that about 45% might have been prevented if every warning sign had been ruled out first. Physiotherapists' international framework says these problems "are rare but are an important consideration as part of patient examination" (a corrigendum to it exists, which we couldn't read). Case reports show that an event followed a treatment, not that the treatment caused it, or how often.
Sources 23, 27, 28, 8, 29, 30, 31, 32
When it isn't the adjustment: the causes the warning signs cover
Neck pain and headaches have causes no treatment created. The NHS lists a drooping face, a weak arm and slurred speech as the main signs of a stroke, and says to call 999 if you've had signs of one within the last 24 hours, even if they've stopped. Taking too many painkillers is one of the causes of headache the NHS lists, and a headache with jaw pain when eating or a sore scalp needs an urgent appointment. A hot, swollen joint with sudden severe pain can be an infection, with a high temperature, although not everyone has one. NHS inform asks for an urgent appointment for clumsy hands, or numbness, pins and needles or weakness in the arms that is getting worse, and the NHS says to see a GP for neck pain that hasn't gone after a few weeks, or comes with pins and needles or a cold arm.
A stiff neck with a very painful headache, a very high or very low temperature, a rash that doesn't fade or bright lights that hurt can be meningitis, and chest pain spreading to the arms, neck or jaw can be a heart attack: both are 999 calls, the NHS says. After a neck injury, NHS inform asks for a 999 call if the person is unresponsive, has severe neck pain or can't move their head, or fell from a height such as 5 or more stairs, and NICE's spinal injury guideline lists what puts someone at high risk of a broken neck, from being 65 or over to a dive, a high-speed crash or a bicycle collision. A new headache with a sore scalp, jaw pain when eating or problems with sight can be temporal arteritis, which the NHS says up to 1 in 5 people with polymyalgia rheumatica develop, and the NHS says to see a GP for pain and stiffness that lasts more than a week; polymyalgia rheumatica is very rare under 50.
The NHS cervical spondylosis page asks for a 999 call for new problems walking, loss of bladder or bowel control or a sudden lack of coordination, such as trouble buttoning a shirt, and for an urgent GP appointment or NHS 111 for severe neck pain that starts suddenly or gets worse quickly, heaviness or weakness in the arms or legs, pins and needles in an arm with neck or arm pain, or pain between the shoulder blades. Chest pain or other symptoms of angina that come and go need NHS 111, the NHS says. The Chartered Society of Physiotherapy lists the rare signs that need a doctor: severe pain that is constant or disturbs sleep, a fever or unexplained weight loss, or a history of cancer, inflammatory arthritis, a weakened immune system or a violent injury. If you think you had a mini stroke (a transient ischaemic attack, or TIA) whose signs have passed and you didn't get advice at the time, the NHS asks for an urgent GP appointment.
An NHS physiotherapy leaflet on a pinched nerve in the neck says new symptoms are likely to settle within 6 to 12 weeks, and asks for urgent help for weakness or numbness that is getting worse, a fever with no other explanation, or severe pain that rest and painkillers don't ease. Headaches several times a week or severe ones, or a throbbing pain on one side with feeling sick and finding light or noise painful, can be another kind of headache, such as migraine, and need a GP, the NHS says. And a lump in the neck, a hoarse voice or difficulty swallowing that isn't getting better, or pain in the front of the neck, needs a GP, as the NHS thyroid cancer page says; these symptoms are very common and usually have other causes.
Sources 33, 34, 35, 36, 37, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64
When a scan helps, and how it usually goesStrong evidence
Not for soreness, stiffness or a mild headache after an adjustment: guidelines don't advise a scan for neck pain without warning signs, as our neck pain guide says, and the Royal College of Chiropractors' standard says imaging shouldn't be "requested routinely for patients with acute neck pain". The warning signs need emergency assessment in hospital, where scans of the brain and neck arteries decide what it is; the American Heart Association lists ultrasound, computed tomography (CT) angiography, and magnetic resonance imaging (MRI) with MR angiography as useful tests. A scan can't show a misalignment that a manipulation corrects.
Most reactions start within 4 hours and three quarters have gone within 24. If the neck pain itself flared, the NHS says "Most neck pain only lasts a few weeks", and NHS inform says "Most problems should have improved within 8 weeks". In seven groups of people followed from the start of new neck pain, average pain fell from 64 out of 100 to 35 by about 6 and a half weeks, but averaged 42 at 12 months, so it often lingers or comes back; in the Dutch neck study, about two thirds of patients were recovered at 3 and 12 months. The GCC says "If you feel your condition has not improved within a few weeks of starting treatment, your chiropractor should discuss other possible care options or refer you to another healthcare professional". No one can promise a date.
Sources 38, 18, 3, 37, 36, 39, 1, 10
