What is loss of muscle mass?

Loss of muscle mass means that your body contains less muscle over time.

You naturally start to lose muscle mass slowly from around 30 years of age and more quickly after age 50. In females, muscle mass is lost more quickly with menopause.

For some people, loss of muscle mass causes physical weakness. Their muscles no longer work well, and they have difficulty doing physical tasks. This is known as sarcopenia.

Loss of muscle mass can also happen with some health problems — it is not always related to ageing.

What causes loss of muscle mass?

Loss of muscle mass happens when your body breaks down protein in muscle faster than it replaces it. Over time, muscle tissue may also change and become weaker.

This may be caused by ageing and not being physically active. It is also associated with both malnutrition (not getting enough nutrients) — especially not having enough protein in your diet — and obesity (being very overweight for your height).

Other reasons people lose muscle mass are noted below.

Weight loss and weight loss medicines

Weight loss can lead to muscle loss — when you lose weight, you are likely to lose muscle as well as fat.

It is unclear whether injected medicines for weight loss (such as semaglutide, liraglutide and tirzepatide) cause more muscle loss than weight loss alone. Research is still evolving on the effect of these medicines on muscle loss.

Other medicines

Some other medicines are known to cause muscle loss, including:

• corticosteroids such as prednisolone
• sulfonylureas and SGLT2 inhibitors (used to help manage diabetes)
• hydroxychloroquine (used to treat malaria, rheumatoid arthritis and some other inflammatory conditions)

Health problems

Many health problems can cause muscle loss in different ways. Some health conditions make it hard to be physically active or eat enough. Chronic (long-term) inflammation can cause muscle loss and weakness. Some conditions affect the way nerves send signals to muscles, causing muscles to break down.

Conditions that may cause muscle loss include:

• cancer
• heart failure, chronic kidney disease and chronic obstructive pulmonary disease (COPD)
• diabetes
• stroke
• inflammatory conditions — such as rheumatoid arthritis and dermatomyositis
• neuromuscular disorders — such as muscular dystrophy, spinal muscular atrophy and Charcot-Marie-Tooth disease
• problems with the central nervous system — such as multiple sclerosis and spinal cord injury

When should I see my doctor?

If you feel you are losing strength, don't assume it's just a natural part of getting older. See your doctor for a check-up.

Your doctor can do some simple tests to work out whether you may be experiencing muscle loss. These tests may include:

• using a hand-held device to measure how strong your grip is
• asking you to stand up from a sitting position without using your arms
• timing how fast you can walk
• timing how long it takes you to get up from a chair, walk 3 metres, turn around, walk back and sit down again

If you have a health condition that may cause muscle loss, talk to your doctor about what you can do to stay strong.

At certain ages, your doctor or local clinic may invite you to have a routine health assessment. This is a good opportunity to check your overall health, including your muscle strength.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

When to seek urgent care

If you have low muscle mass and you have had a fall or injury, see your doctor immediately or visit an urgent care clinic.

If you need to see your doctor but cannot wait for an appointment, you may be able to get treatment at a Medicare Urgent Care Clinic. Use the Service Finder to find your nearest one.

How is loss of muscle mass treated?

If you have been diagnosed with low muscle mass or sarcopenia, there are several things you can do to improve your strength.

Self-care at home

Exercise is very important for improving muscle mass and strength, especially resistance (strength) training. It's also important to do aerobic exercise. Aim for 2½ hours of aerobic exercise per week, as well as resistance training 3 times a week. It may be helpful to see an exercise physiologist or personal trainer to design an exercise program that's right for you.

Eating a healthy, balanced diet rich in protein can help improve muscle mass. If you can't get enough protein into your diet, a protein supplement may help. Your doctor may refer you to a dietitian to help you get all the nutrients you need.

Medicines for loss of muscle mass

Currently there are no medicines that have proven to improve muscle mass. Supplements such as vitamin D, creatine and omega-3 fatty acids have been suggested, but there is not enough evidence yet that they help.

In some females, menopausal hormone therapy (MHT) may play a role in treating low muscle mass. Some plant-based hormone products (phytoestrogens), such as soy protein, may also help. Talk to your doctor if you are going through menopause and have low muscle mass.

What are the complications of loss of muscle mass?

Losing muscle can lead to frailty. This is where several body systems are affected as you get older, leading to health difficulties. Frailty makes it hard to cope with physical challenges and stresses.

Muscle loss can also lead to:

• falls
• fractures
• a higher chance of needing to go to hospital

Read more about tips and products to help prevent falls at home.

Many people with low muscle mass also have osteoporosis, leading to more severe complications.

Can loss of muscle mass be prevented?

You can prevent loss of muscle mass by:

• eating a healthy, balanced diet with enough protein
• getting regular exercise, especially resistance training
• getting health advice when trying to lose weight

It's especially important to do regular exercise if you spend a lot of time doing sedentary (sitting or lying down) activities, such as working at a desk for several hours each day.

If you are trying to lose weight, make sure you are eating enough protein and doing exercise, so you don't lose muscle. This is especially important if you are using injected medicines for weight loss. Side effects of the medicine can make it harder to eat protein-rich foods. It may also be harder to exercise if the medicine makes you feel tired.

In some females, menopausal hormone therapy (MHT) may help prevent muscle loss. Talk to your doctor about whether this treatment is right for you.

If you need to spend time in hospital or on bed rest, ask your doctor about supplements you can take and exercises you can do to prevent muscle loss during this time.

Read more about exercise for older people and how to get started.

Resources and support

Visit Musculoskeletal Health Australia for information and support for people living with muscle and joint problems.

Find out more about preventing age-related muscle loss from Get Active Victoria.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.

Languages other than English

Musculoskeletal Health Australia provides information about diet, exercise and other topics in a range of community languages.

Information for Aboriginal and/or Torres Strait Islander peoples

Visit LiveUp for resources and help as you get older for First Nations people.

Check out the Ironbark Program for preventing falls among Aboriginal and/or Torres Strait Islander peoples.