ST-504 safety guide
How should pain change the next step?
Pain is a stop signal, not a reason to increase pressure or keep testing the device.

Pause the session
Do not continue because time remains.
Check the physical setup
Fit and equipment may explain discomfort.
Use the right escalation
Symptoms may require professional guidance.
Pain should stop the session. It should not be treated as evidence that a stronger setting is needed. The cause may be fit, pressure, skin condition, injury, or another health issue that a general product page cannot identify.
Make one safe equipment check
After stopping, check whether the sleeve is twisted, folded, too tight, or positioned incorrectly. Look at the tubing and connectors. Check for visible damage. Do not restart while a significant symptom remains.
The setup guide covers physical placement. The troubleshooting guide covers observable faults. The safety guide covers the wider suitability question.
Describe the event without diagnosing it
Record where the pain occurred, when it began, the selected controls, the session duration, the sleeve position, and any skin change. “Pain appeared near the upper edge after five minutes” is useful. “The device caused poor circulation” is a conclusion the note cannot establish.
What makes the note useful
Record whether the pain was sharp, burning, pressure-like, or associated with a visible skin change. Record whether it stopped after the sleeve was removed. These words do not diagnose the cause, but they help a professional or support person understand what happened and which question needs attention first.
Seek appropriate professional guidance for persistent, severe, or worsening pain. General FDA medical device information does not determine the cause of an individual symptom.
Pain that stops after repositioning still deserves a careful equipment check. Pain that continues after stopping is no longer only a control question. Keep the sleeve, tubing, and controller available for inspection, but do not restart the session to compare settings. The safest record is the event timeline and the action taken.
If pain is severe, sudden, or worsening, use urgent local guidance. Do not wait for a product reply to decide what the symptom means.
For milder pain that resolves, keep the note and review the physical setup before any future session. A resolved event is still useful information.
Do not delete the note simply because the device later appears normal. The timing may help identify a fit or support issue.
If the person cannot describe the pain clearly, stop and ask another responsible adult or professional for help.
Do not resume until the next step is clear.
Record the decision and the time before closing the note.
Keep the note factual and available for follow-up.