Adverse Events Associated with Therapeutic Dry Needling
Boyce et al. · The International Journal of Sports Physical Therapy · 2020
Evidence Level
MODERATEOBJECTIVE
To determine and report the types of adverse events associated with therapeutic dry needling
DURATION
6 weeks of data collection
TREATMENTS
20,494 dry needling sessions analyzed
🔬 Study Design
Certified physical therapists
n=420
Self-report of adverse events during dry needling
📊 Results in numbers
Minor adverse events
Major adverse events
Bleeding (most common)
Hematomas
Pain during needling
Percentage highlights
📊 Outcome Comparison
Rate of minor adverse events
Rate of major adverse events
This study showed that dry needling is a very safe technique. Although small bleeds and hematomas are common (occurring in about 1 in 3 treatments), serious events are extremely rare (less than 1 case per 1,000 treatments). This makes dry needling much safer than pain medications.
Article summary
Plain-language narrative summary
Dry needling is a technique that uses thin filiform needles to stimulate myofascial trigger points, differing from acupuncture by focusing on specific muscular structures rather than energy meridians. The methodology involved prospective data collection over six weeks, with physical therapists completing weekly electronic questionnaires about minor adverse events (bleeding, hematomas, pain) and major events (pneumothorax, infections, prolonged worsening). Participants had a mean age of 38 years, with 12.1 years of physical therapy experience and 2.7 years of practicing dry needling. The majority (82%) worked in orthopedic clinics.
The results showed that minor adverse events occurred in 36.7% of treatments, with bleeding (16%), hematomas (7.7%), and pain during the procedure (5.9%) being the most frequent. These events are considered normal and expected after needle insertion. Major adverse events were extremely rare, occurring in less than 0.1% of cases (approximately 1 in 1,000 treatments). The most reported major events included prolonged worsening of symptoms, fainting, and forgotten needles in the patient.
Notably, there was no association between the frequency of adverse events and practitioner characteristics such as age, education, years of practice, or level of training. When compared to other pain treatments, dry needling demonstrated a superior safety profile: opioids cause adverse events in 78% of cases, NSAIDs in 35%, while dry needling presented serious events in less than 0.1%. This study significantly expanded the knowledge of safety, since previous studies were limited—Brady et al. (2014) analyzed only 39 therapists and found no major events, possibly due to insufficient sample size.
The clinical implications are important: qualified practitioners (in the context of the study, certified physical therapists) can advise patients that minor events such as light bleeding are expected, but serious complications are extremely rare. The study recommends that practitioners develop protocols to track used needles, prepare to manage vasovagal responses, and adequately inform patients about risks. In the context of the opioid epidemic, these findings strengthen dry needling as a safe alternative for treating musculoskeletal pain.
Strengths
- 1Large sample with more than 20,000 treatments analyzed
- 2Prospective design with real-time data collection
- 3Anonymity of participants allowing honest reporting
- 4Clear categorization between minor and major events
- 5Direct comparison with other pain treatments
Limitations
- 1Low response rate (3%) potentially generating selection bias
- 2Self-report by therapists may underestimate events
- 3Definitions of minor adverse events are not very specific
- 4Decline in event reporting over the 6 weeks
- 5Convenience sample limiting generalization
Expert Commentary
Dr. Marcus Yu Bin Pai
MD, PhD · Pain Medicine · Physical Medicine and Rehabilitation · Medical Acupuncture
▸ Clinical Relevance
The safety profile of dry needling across more than 20,000 sessions provides exactly the type of data we need to support the risk-benefit conversation with patients and service managers. Minor adverse events in 36.7% of treatments—predominantly mild bleeding and hematomas—are biologically expected after the insertion of a filiform needle into vascularized tissue and do not, in practice, constitute barriers to continuing treatment. The number that really weighs in clinical decision-making is that of major events: less than 0.1%. When we compare it to the profile of nonsteroidal anti-inflammatory drugs and, especially, opioids, dry needling emerges as a substantially lower-risk option for musculoskeletal pain. This has direct impact on populations with pharmacologic contraindications—patients with liver disease, kidney disease, those on therapeutic-dose anticoagulation—where needling intervention gains concrete therapeutic ground.
▸ Notable Findings
Two findings are particularly striking. First, the absence of association between frequency of adverse events and practitioner characteristics—age, years of experience, level of training—suggests that the inherent risk of the procedure is relatively constant once basic competence is established, which simplifies reasoning about minimum required credentialing. Second, among major events, the most representative were prolonged worsening of symptoms, vasovagal syncope, and forgotten needles in the patient—not pneumothorax or serious infections, as the lay imagination tends to anticipate. This redirects preventive efforts: the safety protocol that matters most is not surgical preparation, but rather rigorous tracking of needles used per session and routine management of vasovagal responses, which any pain service should already have incorporated.
▸ From My Experience
In my practice, I have used dry needling of trigger points integrated into the musculoskeletal rehabilitation program for more than fifteen years, and the adverse event profile described in this study is consistent with what we observe in our service. Pinpoint bleeding and discrete hematomas are so common that we include them in the informed consent as expected outcomes, not as complications. I typically see significant clinical response from the third or fourth session, with a complete cycle usually lasting between eight and twelve sessions for chronic myofascial pain. For vasovagal syncope—the most preventable major event—we adopt the protocol of mandatory reclined position for patients with a history of lipothymia or high procedural anxiety. I systematically combine with eccentric exercise and, when applicable, with periarticular block; I rarely indicate isolated needling. The patient who responds best, in my experience, is the one with localized myofascial pain and a palpable taut band, without predominant central component—in these cases, the expectation of response is high and the risk, as this work documents, is genuinely low.
Full original article
Read the full scientific study
The International Journal of Sports Physical Therapy · 2020
DOI: 10.26603/ijspt20200103
Access original articleScientific Review
Marcus Yu Bin Pai, MD, PhD
CRM-SP: 158074 | RQE: 65523 · 65524 · 655241
PhD in Health Sciences, University of São Paulo. Board-certified in Pain Medicine, Physical Medicine and Rehabilitation, and Medical Acupuncture. Scientific review and curation of every entry in this library.
Learn more about the author →Medical disclaimer: This content is for educational purposes only and does not replace consultation, diagnosis, or treatment by a qualified professional. Some information may be assisted by artificial intelligence and is subject to inaccuracies. Always consult a physician.
Content reviewed by the medical team at CEIMEC — Integrated Centre for Chinese Medicine Studies, a reference in Medical Acupuncture for over 30 years.
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