Hypotonia means decreased muscle tone. It’s often the symptom of an underlying medical condition. Hypotonia and muscle weakness aren’t the same, although muscle weakness is a symptom of hypotonia. Treatment can improve symptoms over time.
Hypotonia is poor muscle tone. People diagnosed with hypotonia don’t show resistance when joints in their body move. Another term for hypotonia is “floppy infant syndrome.”
Muscle tone is the amount of resistance (tension) to the movement your muscles have at rest. If you relax your left arm and use your right arm to pinch your bicep, the resistance you feel is your muscle tone. For people diagnosed with hypotonia, pinching their bicep would feel soft, without any resistance.
Muscle tone is your body’s response to force and allows you to maintain your posture to sit and use your reflexes, like moving your arms and legs, and helps regulate the function of organs in your body.
If you have poor muscle tone, your arms and legs appear droopy, similar to a rag doll.
Your baby might have trouble sitting upright, keeping their head up and bending their elbows and knees.
Muscle weakness and hypotonia aren’t the same. Muscle weakness is a lack of strength in your muscles and is often a symptom associated with hypotonia.
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Hypotonia is present at birth, and healthcare providers diagnose hypotonia most frequently during early infancy before your child is six months old.
Hypotonia can also affect adults.
Hypotonia is the most common condition that affects a newborn’s motor skills. The exact rate of occurrence is unknown, as hypotonia is often a symptom of another condition.
Hypotonia, as a condition on its own, could identify as a disability because it can affect how a person performs their daily tasks. It’s extremely rare for a baby to have a hypotonia diagnosis without an underlying condition associated with it.
Hypotonia, as a symptom, isn’t a disability, but the underlying diagnosis could be a disability.
Hypotonia doesn’t affect a person’s intellectual abilities.
Children with hypotonia have symptoms where their body resembles a rag doll. Healthcare providers might refer to your baby being “floppy” from their diagnosis. Symptoms of hypotonia include:
Children diagnosed with hypotonia may have delayed developmental milestones that affect their motor skills, including:
A communication error between the pathways that control movement causes hypotonia. These pathways connect the brain, spinal cord, nerves and muscles. Causes of hypotonia include:
Hypotonia is usually a symptom of another condition. These conditions can be genetic and congenital (present at birth). Some conditions cause damage to nerves and the brain as your baby grows, resulting in hypotonia as a symptom. These conditions include:
Other conditions that can cause hypotonia include:
Diagnosis of hypotonia occurs early after your child is born or before they turn six months old. Your healthcare provider will examine your baby for physical symptoms of the condition in your child’s muscles by observing their:
Your healthcare provider will also examine your family’s medical and genetic history and identify if the condition was the result of any complications that occurred before your baby was born or during delivery.
If your healthcare provider suspects hypotonia, they’ll take steps to diagnose the underlying condition that caused hypotonia as a symptom. Tests could include:
After a hypotonia diagnosis, your healthcare provider will test for the underlying condition that caused hypotonia as a symptom. Your healthcare provider will begin treating the underlying condition, followed by symptomatic treatment to address symptoms, including:
As babies diagnosed with hypotonia might have trouble eating and swallowing due to their weakened muscle tone, your healthcare provider might place a tube in your child’s nose or directly into their stomach to provide nutrients to your baby.
Hypotonia is a lifelong condition, but muscle tone can improve over time with successful treatment for the underlying condition that caused your baby’s symptoms.
There isn’t a way to prevent hypotonia because it’s often the symptom of an underlying condition, which can be genetic. Genetic conditions are not preventable. If you plan on becoming pregnant and want to understand your risk of having a child with a genetic condition, talk to your healthcare provider about genetic testing.
If you’re pregnant, you can take steps to prevent having a child prematurely by:
The prognosis of hypotonia varies based on the underlying diagnosis. Hypotonia is a lifelong condition that can get better with treatment. Most babies who have a hypotonia diagnosis show great improvement in their muscle tone as they get older.
If your child receives an underlying genetic condition diagnosis, there’s a chance that symptoms of hypotonia could worsen over time. To better understand your child’s diagnosis, talk with their healthcare provider or a genetic counselor.
Take extra care when lifting your baby because babies with hypotonia are more delicate, with soft spots where their muscles are, causing them to appear floppy. If you lift a baby with hypotonic by placing your hands under their armpits, they can slip out of your hands, as they don’t have muscle resistance there. Your baby will have a difficult time supporting themselves in a way similar to babies who don’t have the condition. Follow treatment recommended by your healthcare provider to improve your baby’s muscle tone over time.
If you notice your baby’s muscle tone decreases or your baby is weaker than normal, visit your healthcare provider. This is especially important if your child was able to accomplish certain motor skills like sitting upright or grabbing objects, and then suddenly, they cannot perform those tasks.
Both babies and adults can have a hypotonia diagnosis. Babies who receive a hypotonia diagnosis retain their diagnosis for their entire life, even if symptoms improve. New hypotonia diagnoses in adults could result after a traumatic injury, brain tumor, stroke or condition like Parkinson’s disease.
Symptoms may be similar for both babies and adults, where they’re clumsy, have trouble getting up from lying down or sitting, and show increased flexibility in their elbows and knees.
Treatment with physical and occupational therapy, along with treating the underlying condition, helps conditions in babies and adults improve over time.
Hypotonia is weak muscle tone and hypertonia is too much muscle tone. If your baby has hypertonia, their muscles are stiff and it’s difficult for them to move their arms and legs.
A note from Cleveland Clinic
As a parent, it may be stressful to see your baby limp and weak, similar to a rag doll. Your healthcare provider will work closely with you to provide an accurate diagnosis of the underlying condition for your baby so they can receive treatment. Over time and with treatment, your baby will improve with support from their caretakers until they can support themselves.
Last reviewed by a Cleveland Clinic medical professional on 12/29/2021.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy