The brain is a funny thing.

No matter where we go, or what we do, we’re stuck with it; this private prism by which we see and understand the world around us.

From this 1400 gram grey mass we can have up to 60,000 thoughts a day. There are some we might decide to share, and others that we keep to ourselves.

But how do we determine what sort of brain behaviour is ‘normal’, given we have nothing, really, to compare it to?

What thoughts, feelings, anxieties and actions are serious red flags, that indicate we might need some help with our mental health?

According to the Bureau of Statistics, about 45 per cent of Australian adults will experience mental illness at some point in their lifetime.

For some, symptoms of their mental illness began surfacing in childhood, meaning that they’ve never known anything different.

Mamamia spoke to Australian psychologist Tahnee Schulz about some of the key indicators – which might not be immediately obvious – that an individual might need to seek professional help for their mental health.

While these symptoms pertain mostly to depression and anxiety, the two most common mental illnesses among adults, they are also applicable to mental health conditions more broadly, such as post-traumatic stress disorder, obsessive compulsive disorder and bipolar disorder.

1. Changes within yourself

“If they are thinking, feeling or behaving differently to how they would for two weeks or more,” Schulz says, that could be a significant warning sign.

For example, if an individual finds themselves no longer enjoying things they usually would, like exercise or hanging out with friends, that’s not something to dismissed.

Waking up one day and feeling a little depleted of energy might be normal, however, if this persists for a few weeks, it could be a sign of a mental health condition.

Changes in appetite is often a warning sign Schulz says, like “losing your appetite or having a high increase in appetite,” could be an indication that your mental health is affecting your adrenal glands or thyroid.

An illness can start out as some relatively subtle changes, like a lack of motivation or irritability, and intensify over time.

2. Constantly feeling tired

Fatigue, according Schulz, is something that has been normalised in our culture, often to the detriment of our health.

It’s easy to think you just need an extra coffee, but if you feel tired all the time that’s a sign something isn’t right.

Schulz describes, “feeling like you can’t get out of bed, you can’t concentrate, you can’t make decisions or work out what you really want anymore because your brain just feels really foggy and tired,” as a symptom of mental illness.

People often equate tiredness with a physical health issue, like anaemia, hypothyroidism, sleep apnea, glandular fever or diabetes, which are indeed all possible causes.

But it is all possible that fatigue, particularly not being able to get out of bed or having disrupted sleep, is a sign of a mental health condition.

3. Finding basic self care really difficult

This symptom is related to a lack of energy.

Schulz says if you’re unable to apply “simple self care… like having a shower, eating good quality food, going for a walk or getting out in the sunshine…” that’s often one of the most telling signs that your mental health is suffering.

While it might be ‘normal’ to complain that Mondays are difficult (they are), if every weekday is a challenge, from getting dressed to catching the bus, then that’s something worth seeing a doctor about.

4. Pain

Aches and pains can easily be considered just an unavoidable part of day-to-day life, particularly if we’re growing older.

But pain, for example frequent headaches or backaches, can be related to health conditions like depression or anxiety.

Some sufferers, according to Schulz, feel a “huge amount of pain inside [their] body,” and also experience physical pain like reflux and heartburn.

Gut issues, from stomach aches to irregularity, can also be related to mental health.

5. Always feeling guilty

Guilt is of course a universal human emotion. It would be very strange for someone to never feel guilty.

Like shame, guilt feels deeply personal, and connected to specific experiences or relationships.

But if guilt is pervasive and keeping you up at night – that is not normal.

One hurdle to people seeking mental health treatment options are feelings of guilt and shame, Dr Schulz says. In some environments, people can be branded as “needy” or “mean” if they’re suffering. “It can be very hard for you then to realise that you have a mental health condition,” Shulz says, “because you label yourself the same way. You think ‘I’m needy and I need to be quiet about this’.”

But all of these behaviours and feelings are actually symptomatic of a mental health condition, rather than signs you’ve done anything ‘wrong’.

6. Specific self talk

With all the thoughts we have every single day, it’s unsurprising that some of them are negative.

But there are specific thoughts that are considered red flags by psychologists. They are:

“I’m worthless”

“Nobody likes me”

“It’s all my fault”

“I ruin everything”

“Things will never get better”

“I don’t want to live anymore”

“People are judging me”

“I don’t fit in”

“I don’t belong”

“This self talk is really destructive,” Schulz says, and often times we don’t even recognise just how awful our inner dialogue really is.

These statements in particular are what Schulz terms “final statements” suggesting that the individual doesn’t have any hope.

In order to identify your ruminating thoughts, it’s recommended you practice mindfulness or write a thought diary.

So, what do you actually do if these symptoms are familiar?

A simple first step is to visit your GP. They can perform a general check up, to explore the cause of these symptoms.

If it is looking like a mental health condition, the GP can provide a treatment plan.

According to the Department of Human Services, a patient can claim up to 10 sessions per calendar year with a mental health professional.

It’s important to note that health professional sets their own fees, so they may only be able to cover some of the cost. If they bulk bill, you won’t have to pay anything.

Schulz says “You’re not born to connect to everybody,” and it may take some time to find the person suited to you.

Schulz recommends an online resource called Lysn (welysn.com) which has an offering of over 500 psychologists. Based on personality factors and your specific challenges, Lysn matches individuals with the right psychologist, and also provides patients with a “matching session” where you can speak to a psychologist non-clinically for 20 minutes to see if you actually connect with them.

If you are under the age of 25, you can contact your local headspace centre, which offers free and confidential treatment.

If any of your symptoms include suicidal or homicidal thoughts, then contact 000 or your local emergency health service.

If you think you may be experiencing depression or another mental health problem, please contact your general practitioner or in Australia, contact Lifeline 13 11 14 for support or beyondblue 1300 22 4636.