About Bedwetting Alarms — Understanding and Using.

About Bedwetting Alarms — Understanding and Using.

What is a Bedwetting Alarm:

A bed wetting or enuresis alarm is intended to detect a discharge of urine from a person. Such discharges may not be noticed by the person if the person is sleeping or is unable to sense or respond to this event. Typical cases of unnoticed discharge of urine may be from

  • Children, who have not yet developed the ability to sense bladder pressure when they are asleep, and so do not wake up in time to get up and go and relieve themselves in a toilet.
  • Older children and adults who are incontinent and unable to control the natural discharge of urine. This may be the result of age, disabilities, or just not being able to sense bladder pressure.

The purpose of a bedwetting or enuresis alarm is to signal an alert when such urination occurs. A bedwetting alarm has a sensor that is positioned at or very close to the spot where urine leaves the body. When urine reaches the active part of the sensor, it sends a signal to the alarm which then alerts.

How a Bedwetting Alarm Works:

All bedwetting alarms work on a simple principal. If an electrical insulator such as air or dry briefs separates two electrical conductors having a small voltage across them, this results in an electrical open circuit. So no current will flow between the conductors to any electric circuit to which they are attached. When the insulator (briefs) gets wet, electricity flows more easily between the two conductors, and this triggers the sensor to create the alert. Urine contains electrolytes (salts) which makes it a better conductor of electricity than plain water. Better alarms will distinguish between water and urine (or salt water). Better alarms can also distinguish between a “rush” or quick increase of urine as opposed to a slow increase in wetness as may be caused by perspiration. Always remember that if the urine does not reach the activating part of the sensor, the alarm cannot “know” that it should alert.

Types of Alarms:

There are three broad categories of bedwetting and enuresis alarms:

  • Wired alarms, where a wire connects the sensor, attached to briefs worn by the patient, to the alarm which is attached to the patient’s clothing.
  • Wireless alarms, where the sensor triggers a wireless transmitter which sends a wireless signal to a receiver, which then generates the alarm. The receiver is usually not attached to the patients clothing, and may be AC powered.
  • Pad alarms, sometimes called a bell and pad. The patient sleeps on the pad and allows urine to soak through the patient’s clothing to the wetness-sensing pad, which then activates an alarm that is attached to the pad.

There are three basic types of sensors:

  • Clip sensors, where a stainless-steel clip at the end of the sensor wire is clipped onto the patient’s briefs. The clip design and actual attachment mechanism can vary, as can the ease and effectiveness of its use. Clips can be washed with soap and water and towel dried. The mechanical parts must be used carefully to prevent damage, and may cause difficulties in reaching areas for cleaning. I am not aware of any respectable manufacturer who uses metals that “rust” their clip, as may be suggested by unethical persons or sellers.
  • Magnetic sensors, where the sensor is attached to a set of magnets, with the briefs being clamped between these and another set of magnets. Their flat surfaces make these the easiest sensors to use and clean.
  • Pads, which sense wetness when it contacts the wires or electrical conductors built into the pad. The pad is placed on a bed and the patient is expected to lie on it. If the patient wears any clothing, the urine must pass through the clothing to get to the pad. This can be unpleasant and messy, and also uncomfortable for the patient.

A variation on this pad is a small pad which must be held to the briefs using a sticky mini-pad or sticky tape. Here there can be issues with attaching the pad to the briefs, the pad remaining in place, general messiness, and the continuing costs of mini-pads and sticky tape.

Another more substantial variation is the “wired” briefs , where wires are sewn into cotton briefs so that when urine reaches the briefs the attached sensor is triggered. This sensor is typically wireless. The briefs are worn like regular briefs and have a large surface area on which the urine can fall.

Types of Alerts:


A sound alert is generated. The sound can be music or a synthetic sound which can alert a user and/or a caregiver. A volume control, which allows the level of sound to be changed, is desirable. Several sound levels (volumes) are desirable. The volume should be loud enough for the parent or caregiver to also hear it, so that support can be provided to the child or patient who may not respond to the alarm. The loudness of an alarm should be considered in terms of the distance from where the alarm is attached or placed to the ear of the user. Most alarm manufacturers do not provide the loudness level of their alarm. I must assume that this is because it might embarrass them as being too soft. It is easier to rely on word-of-mouth and promotion which can be easily manipulated. For the few manufactures that do provide loudness levels, they range from 87 dB to 76.9 dB at a distance of 8 inches, a typical distance from the alarm worn on clothes to the ear. 87 dB should be adequate, while 76.9 dB is soft. As an alarm gets physically smaller and the battery smaller and weaker, expect a softer sound. Statements about LOUD sounds without providing any measurements of the loudness are misleading.


Alarms can also generate vibrations. When the alarm box is touching the body, this vibration can be felt. The vibration produced by small battery operated alarm boxes is weak, as there is inadequate power and physical space in these small alarms to produce a strong vibration. It is similar to the vibration produced by a pager or cell phone. Many patients who are not conscious, particularly children who are fast asleep, may not notice the vibration. As an alarm gets physically smaller and the battery smaller and weaker, expect a weaker vibration. Statements about STRONG vibrations coming from a small battery powered alarm are misleading. A strong vibration can be obtained by using of a “bed-shaker.” This device can be placed under a pillow or at a corner of the bed between the top mattress and its foundation. These vibrations are very effective. These devices can be attached to and work with some AC powered bedwetting alarms. Two such alarm systems discussed here, the DryBuddyFLEX and the Rodger wireless, can power bed-shakers that are plugged into them.


A strong light could wake up a sleeper. A light produced by a small battery operated alarm is typically an L.E.D. which is placed several inches away from the eyes, and not even in front of the shut eyes. This light can serve to provide information about the alarm. It is very misleading to suggest that these weak lights will wake a sleeping child.

Common Mistakes by Parents and Caregivers in Buying and Using a Bedwetting Alarm:

  • “The alarm alerts after my child urinates. The alarm is useless. It should alert before my child urinates.”An alarm can only determine that the child has urinated after the urine reaches the alarm’s sensor. Placing the sensor correctly is a great help. Also consider using sensors which have a larger area over which the urine can be detected.
  • “The alarm should wake my child.” Should is correct. And some children are easier to wake than others. Alarms worn on clothing are frequently positioned within 8 inches from the user’s ear. Consider using an alarm whose loudness level is at least 85 dB for a distance from the typical location of the alarm to the user’s ear. This should work. Maybe. Consider using a bed-shaker with hard-to-wake children. The low vibrations produced by battery operated alarms are like the vibrations of a cell phone and are unlikely to wake many sleeping children and patients.
  • “The alarm must wake my child and make him get up.” Some children may genuinely not be woken. Others do not want to wake up and may act as though they are asleep. Expecting an alarm to make the child get up and out of bed is unrealistic. It is very important that an alarm be selected and located so that the parent or caregiver can hear the alarm when it sounds. It is the parent’s responsibility to make sure that the child wakes, gets out of bed, etc. Parents and caregivers should not blame an alarm for their irresponsible behavior in not adequately supporting their child or patient.
  • “The alarm stopped working before its warranty is over. This is a useless alarm.” Any device can fail. Failures can occur due to manufacturing defects and also through user misuse and abuse. Treat the bedwetting alarm with care as you would any instrument. It is not a children’s toy. If the failure can be promptly corrected, that is what a user should realistically expect. Select an alarm with a long warranty period.
  • “I got this alarm as I was promised that it would save me significant money after my child’s bedwetting was cured.” The savings after ANY alarm has succeeded are identical. A manufacturer or seller suggesting that such savings would only come about from the use of a particular alarm is misleading the buyer.
  • “I got this alarm as it said that it was Doctor recommended.” Many Doctors recommend bedwetting alarms. Without a significant and verifiable list of Doctors specifically recommending any particular bedwetting alarm, emphasizing this claim is misleading and possibly false.
  • “I got this alarm as it was claimed that it is insurance approved.” FDA registered bedwetting alarms, and possibly others, are accepted by insurance companies. There is nothing unique for a particular brand or model, and stating this is an exaggeration and misleading. More importantly, insurance claims and tax deductions for buying a medical device require a Doctor’s prescription.
  • “This bedwetting alarm is computer controlled. Wow!” Hmm. All modern bedwetting alarms have some form of computer control to govern logical and desirable behavior by the alarm. This is very common.
  • “This alarm must be excellent as it has won numerous awards.” Like the “Doctor recommended”, unless a verifiable list of awards is provided to the reader, this claim is misleading and possibly false. Also look for the quality of the organizations giving the claimed awards and the circumstances under which the awards were given.
  • “This alarm frequently alerts when my child perspires.” Most alarms are still susceptible to false alarms by slight wetness. Perspiration can set them off. Consider an alarm that can identify the difference between urination (the moisture comes rapidly) and perspiration (the moisture comes slowly).
  • “I have to keep on spending more money to keep using this.” A few bedwetting alarms require the user to use supplies continuously when using the alarm. Such supplies are often sticky tapes, sticky pads, and other items that can only be used once and then must be thrown away. Also consider the time and hassle required to apply or use these supplies, an additional “tax” on the user. Sellers benefit from this continuing tax on users. A wise buyer will identify what supplies may be needed and what they may cost over the life of use of the alarm. The seller often encourages the buyer to underestimate how long the alarm may be used so that the buyer ignores these ongoing costs of supplies. I suggest that any buyer should estimate supplies costs over a six-month period and add that to the initial cost of buying the alarm.