TENS Units: A Practical Guide for Women in India

• TENS relieves pain through nerve mechanisms — by 'closing the pain gate' at high frequencies (50–100 Hz) and triggering your body's own endorphins at low frequencies (1–10 Hz).
• It has the strongest evidence for primary period pain, labour back-pain, and some post-surgical pain; evidence for chronic conditions like back pain and fibromyalgia is more mixed.
• Set the intensity to a strong but comfortable tingle — never to pain or muscle twitching. More intensity does not mean more relief.
• Avoid pads over the front of the neck, the chest in people with pacemakers, broken skin, the abdomen or lower back in early pregnancy, and never use it in water or while driving.
• In India, consumer TENS units cost roughly Rs 500–3,500 and are sold without a prescription on 1mg, Apollo, Amazon and Flipkart — try it for 2–4 weeks to see if it works for you.

A TENS unit delivers controlled electrical pulses through self-adhesive electrodes placed on the skin near the painful area or along the nerves that supply it. It is thought to ease pain through two main mechanisms, each dominant at a different stimulation frequency.

Gate control (high-frequency TENS, 50–100 Hz). The gate control theory of pain, proposed by Melzack and Wall in 1965, holds that non-painful sensory signals can 'close the gate' to pain signals in the spinal cord. High-frequency TENS activates large A-beta nerve fibres — the same ones triggered by light touch and vibration. Their signals reach the spinal cord and dampen pain messages travelling along smaller pain-carrying fibres. Relief is usually fast but tends to fade soon after the device is switched off.

Endorphin release (low-frequency TENS, 1–10 Hz). Lower-frequency stimulation, especially at higher intensities, is thought to prompt the body to release its own natural painkillers — endorphins and enkephalins. These bind to opioid receptors in the brain and spinal cord, producing relief that is milder than opioid medicines but comes from within your own body. Onset is slower (about 20–30 minutes) but the effect may outlast the session.

Burst mode combines both, sending brief high-frequency bursts at low-frequency intervals, for effects in between the two.

Beyond these nerve effects, TENS may increase local blood flow, ease muscle tension and spasm, and possibly modulate inflammation — though these play a smaller role.

A realistic word on evidence. TENS has stronger support for some acute pain — post-surgical pain, labour pain, and primary period pain. For chronic pain (long-standing low back pain, fibromyalgia), results are more variable, with some studies showing benefit and others not. This reflects real differences in pain types, individual response, electrode placement, and study design. Crucially, individual response varies enormously: some women get major relief, others little. A short trial is the only reliable way to know your own response.

• Frequency (Hz): low (1–10 Hz) for endorphin relief; high (50–100 Hz) for gate-control relief.
• Pulse width (microseconds, ~50–300): wider pulses recruit more nerves and feel stronger; narrower feel gentler.
• Intensity (amplitude): tune to a strong-but-comfortable tingle — too low does nothing, too high twitches muscles.
• Mode: continuous, burst, modulated, or a preset application mode.

Primary dysmenorrhoea — period cramps with no underlying pelvic disease — affects a large share of women and can seriously disrupt daily life during menstruation. TENS is a safe, drug-free option with reasonable evidence for menstrual pain, useful alongside or instead of NSAIDs.

Where to place the pads. Two pads on the lower abdomen below the navel, on either side of the midline (about 5–8 cm apart), and optionally two more on the lower back over the sacrum or lumbar area. A dual-channel set-up covers the whole pain area.

Settings. High-frequency TENS (about 80–100 Hz) commonly works well for immediate cramp relief. Some women alternate with lower frequency (2–10 Hz) for longer-lasting, endorphin-mediated relief; burst mode can also help. Increase intensity gradually to a strong but comfortable tingle, never to twitching. You may need to nudge intensity up over a session as your nerves adapt — this is normal.

Duration. Use it during pain for 20–60 minutes at a time, several times a day on your most painful days.

Evidence. Cochrane reviews and other analyses suggest TENS can help primary dysmenorrhoea, with high-frequency TENS having the more consistent evidence. The American College of Obstetricians and Gynecologists lists TENS among non-drug options for period pain. Results are often best when TENS is combined with other measures — NSAIDs when needed, heat therapy and other cramp-reducing habits, anti-inflammatory foods, and gentle movement during your period.

Pros and cons. TENS is drug-free (helpful if you can't take NSAIDs because of ulcers or kidney issues), has no systemic side effects, is portable, and is a one-time purchase. On the downside, it doesn't help everyone, you must have the device on hand, and some women find the sensation distracting.

For secondary dysmenorrhoea — period pain from conditions like Endometriosis: Why Diagnosis and Treatment Are So Hard, Adenomyosis vs Endometriosis: Differences, Diagnosis & Treatment, or uterine fibroids — TENS can be a helpful add-on but does not replace diagnosis and treatment of the underlying cause. If you also feel ovary or pelvic pain outside your period, get it evaluated.

TENS has been used in labour for decades as a non-drug pain option. Dedicated obstetric units are designed for labour, with a 'boost' button the labouring woman presses during contractions.

Pad placement. Typically four pads on the back: two over the upper lumbar region (around T10–L1) and two over the sacrum (S2–S4). These match the spinal nerve levels carrying uterine and cervical pain. Placing pads on the back rather than the abdomen keeps it safe for the baby during labour.

How it's used. Low continuous stimulation runs between contractions, with the boost button adding stronger stimulation during them. Controlling the boost herself gives the woman an active sense of control.

Evidence. Cochrane reviews show modest pain relief with high user satisfaction. TENS works best in early to mid labour, especially for labour back pain; it is generally not enough for the intense pain of advanced labour, where an Epidural in India: How It Works, Cost, Side Effects and When to Ask, opioids, nitrous oxide or water immersion may be more effective.

Pros. Completely non-drug, no effect on the baby, allows you to keep moving (unlike an epidural), can be started early at home, and combines well with other methods. Limits: less effective than drugs for severe pain, and pads must come off before water immersion.

In India, obstetric TENS is available at some private hospitals and birth centres but not most. If you'd like to use it, you can buy a unit (about Rs 1,500–3,500) and bring it, with your birth team's approval — discuss it in advance with your obstetrician and labour nurse before your due date.

Avoid obstetric TENS with known fetal compromise, pregnancy complications needing continuous monitoring, epilepsy, or certain cardiac conditions. Note that abdominal or lower-back TENS in early pregnancy is contraindicated; only back placement in late pregnancy for labour is considered acceptable.

TENS is widely used for chronic pain. Evidence varies by condition, but many women report real benefit when it is part of a broader plan.

Chronic low back pain is common in women, partly from childbearing, lifting children, work demands, and posture. Studies of TENS here are mixed — some show modest benefit, others little over placebo. Guidelines treat it as an add-on to exercise, physiotherapy and targeted back exercises, weight management and posture work, not a stand-alone cure. Place pads on the lumbar muscles either side of the spine at the level of pain.

Chronic neck pain is often linked to posture, screens and stress. Place pads over the upper trapezius and neck muscles — and never on the front of the neck (over the carotid sinus or near the voice box), which is unsafe.

Fibromyalgia, a chronic widespread pain condition that mostly affects women, has some supportive evidence for TENS, especially when used during activity to improve function. Guidelines list it as one of several non-drug strategies. See our guide to fibromyalgia in Indian women.

Osteoarthritis of the knee, hand or hip — common in post-menopausal women — can respond to TENS for symptom relief; pads go around the affected joint.

Chronic pelvic pain in women may stem from endometriosis, adenomyosis, interstitial cystitis or pelvic-floor dysfunction. TENS can help symptoms, and pelvic-floor exercises often matter too; specialised techniques such as posterior tibial nerve stimulation are used for some bladder and pelvic conditions. If pelvic pain is ongoing, read chronic pelvic pain: causes and workup.

Post-surgical pain — including after a caesarean (pads placed away from the wound) — can be eased with TENS alongside standard pain relief, sometimes reducing the medicines needed.

A practical approach is a 2–4 week trial of regular use. If you feel meaningful benefit, continue; if not, switch tactics. Because TENS rarely causes harm, the trial is low-risk beyond the modest cost of the device and pads.

• Pacemaker or other cardiac device: relative contraindication — check with your cardiologist first.
• Epilepsy: avoid head and neck placement.
• Pregnancy: no abdominal or lower-back pads in early pregnancy; back placement for labour is acceptable in late pregnancy with obstetric clearance.
• Bleeding disorders, severe peripheral vascular disease, or DVT: consult a doctor before use.

TENS units are widely available in India without a prescription — they are consumer health devices, much like BP monitors or glucometers.

Where to buy. Online: 1mg (Tata 1mg), Apollo Pharmacy, Pharmeasy, Netmeds, Healthkart, Amazon India and Flipkart all stock them, with reviews and home delivery. In person: Apollo Pharmacy, MedPlus, Wellness Forever and medical-equipment stores in larger cities.

What it costs.

• Basic single-channel units: roughly Rs 500–1,500.
• Mid-range dual-channel units with multiple modes: about Rs 1,500–3,500.
• Advanced wireless or multi-modality (TENS + EMS) units: Rs 3,500–15,000.
• Professional/clinical units: Rs 15,000+.

• Period pain that is getting steadily worse, pain outside your period, or pain during sex or bowel movements — possible signs of endometriosis or adenomyosis needing evaluation.
• New, severe, or one-sided pelvic pain, fever, or fainting — seek urgent care.
• Back, joint or nerve pain with weakness, numbness, or loss of bladder or bowel control — a red flag needing prompt assessment.
• Pain that does not improve after a 2–4 week TENS trial, or that keeps you from sleeping, working, or daily activities.
• A pacemaker, heart-rhythm problem, epilepsy, pregnancy, or a bleeding disorder — check with your doctor before starting TENS at all.

• Melzack R, Wall PD. Pain Mechanisms: A New Theory. Science, 1965.
• ACOG — Dysmenorrhea: Painful Periods (FAQ)
• Cochrane — Transcutaneous electrical nerve stimulation (TENS) for primary dysmenorrhoea
• Cochrane — TENS for pain management in labour
• NHS — TENS (transcutaneous electrical nerve stimulation)
• NICE — Osteoarthritis in over 16s: diagnosis and management (NG226)