Which physical signs point to cannabis use?

There is no single physical sign that clearly indicates cannabis use. The BIÖG names possible short-term signs such as a smell of smoke described as sweetish, red eyes, dry mouth, drowsiness and increased appetite. All of these signs can also have other causes, as can complaints such as coughing, a pounding heart or sleep problems. Anyone who pays attention to the body should therefore observe changes, note them and suggest a medical check-up if complaints persist. A single symptom should not be turned into a diagnosis straight away.

Which short-term signs does the BIÖG name?

The BIÖG's prevention page for parents names the following possible short-term signs of cannabis use:

• a distinctive smell of smoke, sometimes described as sweetish
• drowsiness and slow reactions
• conspicuous talkativeness or silence
• excessive silliness and giggling
• red or swollen eyes
• dry mouth
• reduced concentration, lower performance and memory problems
• increased appetite

These signs are clues and offer no proof. Each of them can also be linked to tiredness, an infection, stress or other causes. Anyone who notices these signs in their child should first seek a conversation and not assume use.

Why single signs prove little

Teenagers change a great deal physically and emotionally during puberty. Tiredness, shifting moods or changed sleeping patterns are therefore not evidence on their own. Infections, stress and lack of sleep can produce the same signs. You should take notice when several changes come together or when complaints persist over a longer period.

Airways and lungs

Cannabis smoke puts a strain on the airways. According to drugcom, the substances in the smoke damage the cilia in the airways. These fine hairs clean the airways, and when they are damaged, cleaning becomes harder. The Swiss Infodrog website names as possible consequences a risk of airway inflammation, shortness of breath, chronic cough and bronchitis.

Mixed use with tobacco is especially important. If cannabis is mixed with tobacco, according to Infodrog the same risks apply as for tobacco use alone. Anyone who mixes cannabis with tobacco puts additional strain on the airways and increases the risk of nicotine dependence, according to the feel-ok.ch prevention page.

According to drugcom, there is no final conclusion yet on the lung cancer risk from cannabis use alone. That is no reason for an all-clear. It only shows that research on this question is still open. For parents, this means that a persistent cough in a child should be medically examined, whatever the cause.

Heart and circulation

Cannabis can increase heart rate, according to the DHS. A pounding heart counts among the acute effects, and existing heart problems can worsen in individual cases. According to drugcom, a Canadian study of around 30,000 people shows around 60 per cent higher occurrence of cardiovascular diseases. The researchers themselves point out that their results do not provide evidence of a causal link.

For parents, one practical conclusion follows: if your child complains of persistent racing heart, chest pain or breathlessness, they should be examined by a doctor, whether or not use plays a role. In the case of severe complaints, calling the emergency number comes before any discussion.

Anxiety, restlessness and sleep

The BIÖG names anxiety and panic feelings as short-term risks. If a child often seems anxious or restless, you can raise the question of cannabis in conversation without assuming it straight away.

There is also an established link with sleep. According to drugcom, sleep problems and vivid dreams are among the withdrawal symptoms that can occur after stopping. Whether and how strongly they appear differs greatly between individuals. If your child sleeps badly after a period of use and at the same time seems restless, that is a reason for a conversation.

Mixed use as an amplifier

When cannabis and alcohol are used together, according to the BIÖG this places a considerable strain on the circulation and often leads to nausea and vomiting. If you see such signs in your child, keep the combination in mind. More on this topic is in the article How do you respond to: cannabis is less harmful than alcohol?

Why parents should not diagnose

You can observe changes and raise them. Making a diagnosis is the job of a doctor. A misreading can cost trust, for example when a child is suspected because of flu or exam anxiety. It is therefore more helpful to describe concretely what you see and hold back conclusions. A sentence such as “You've been coughing for three weeks and you're more often tired. Let's have a doctor look at it” is factual and leaves room for answers.

Documenting changes in everyday life

A timeline helps more than individual moments. Note when complaints occur, how long they last and what came before, such as school stress, an argument, a party or a cold. Such notes help the doctor as well as a counselling service, because they show whether something repeats or changes.

Checks, such as searching the room, often strongly damage trust. Before you resort to such measures, it is worth clarifying in a counselling service what is appropriate and whether a conversation can open the way first. How parents handle this question is described in the article May parents search their child's room?

What you can do now

1. Note changes with the date, for example coughing, sleep, mood or weight.
2. Speak to your child before you voice assumptions.
3. Arrange a doctor's appointment if complaints persist or get worse.
4. Tell the doctor what you are observing so that the examination is complete.
5. Get advice if you are unsure how to handle the suspicion.

For a first assessment, you can call the Elterntelefon (parent phone line) of Nummer gegen Kummer on 0800 111 0 550 (anonymous and free of charge). For questions about addiction and drugs, the Sucht & Drogen Hotline helps on 01806 313031 (available around the clock, charged). Further health topics are in the area Health risks.