Mollie King has updated fans on how she is coping with the "heartache" after losing her dad to brain cancer, sharing that "the nights are the hardest".

The Saturdays star and radio presenter, 35, has decided to open up about her grief, rather than just continuing to "keep as busy as possible" to distract herself, in support of Brain Tumour Awareness Month.

King's father was diagnosed with the disease in August last year and sadly passed away three months later.

King shared a picture of her and her dad taking a selfie on Instagram, saying she's "tried not to let [herself] think about losing someone [she] loves."

Sharing that her family "have been utterly heartbroken by what this horrible disease did" to her Dad, King says they want to raise awareness and funds for The Brain Tumour Charity, for which her sister Laura is running the London Marathon in April.

"Our lives will never be the same after losing our beloved Dad and our love and thoughts go out to anyone whose life has also been touched by cancer."

The star first paid a heartfelt tribute to her dad after his death, sharing that he "held on a few extra days" to meet Annabella, who she and cricketer fiancé Stuart Broad publicly welcomed a week prior. She posted a series of pictures with her father to Instagram on Wednesday 30 November, announcing the news.

Brain tumours can seem like one of the most scary health conditions, but thankfully more is being done to raise awareness, including through the recent Lola Pearce storyline on EastEnders.

In October, the late Tom Parker's widow Kelsey also called for more funding into brain tumour research in the UK, after The Wanted singer died at a hospice near the couple’s south-east London home on 30 March at the age of 33, following his diagnosis with stage four glioblastoma. Early detection is key.

Here's what you need to know about brain tumours.

What are brain tumours?

A brain tumour is a growth of cells in the brain that 'multiplies' in an abnormal, uncontrollable way, according to the NHS. There are different 'grades', including one and two that are low grade, and three and four that are high grade.

The two main types of brain tumours are non-cancerous (benign), which are low grade and grow slowly and are less likely to return after treatment.

Cancerous (malignant), meanwhile, are high grade and either start in the brain (primary tumours) or spread into the brain from elsewhere (secondary). These are more likely to grow back after treatment.

What are the symptoms of a brain tumour?

The symptoms of a brain tumour will depend upon which part of the brain is affected, according to Brain Tumour Research.

The most common symptoms are caused by an increase in pressure in the skull prompted by the growth of a tumour in the brain.

Other likely symptoms, which may initially come and go, can include one or more of the following:

• Headaches

• Eye and vision-related problems (such as squinting and double-vision)

• Continuing nausea, vomiting

• Extreme or sudden drowsiness

• Tinnitus (ringing in the ears) or hearing loss

• Unexplained twitches of the face or limbs

• Seizures (fits or faints)

• Appearing to be lost in a deep daydream for a short while

• Confusion

• Loss of balance

• Numbness or weakness in the arms or legs, especially if progressive and leading to paralysis

• Numbness or weakness in a part of the face, so that the muscles drop slightly

• Numbness or weakness on one side of the body, resulting in stumbling or lack of co-ordination

• Changes in personality or behaviour

• Impaired memory or mental ability, which may be very subtle to begin with

• Changes in senses, including smell

• Problems with speech, writing or drawing

• Loss of concentration or difficulty in concentrating

• Changes in sleep patterns

“Depending on which part of the brain the tumour is affecting, the symptoms can vary,” Dr Daniel Cichi from Doctor 4 U adds. “If, for instance, a tumour is located at the frontal lobes this may cause personality and behavioural changes.

“Symptoms can vary greatly amongst patients, but in general, any noticeable changes to your behaviour, mobility, vision or speech should be checked out by your doctor.”

Dr Cichi says that in particular, if you’re experiencing frequent and severe headaches, loss of sensation or movement in your limbs that happens gradually, or progressive weakness on one side of the body, as well as seizures or speech and vision problems, these could indicate a brain tumour. But, he cautions, it’s not always the case.

“Nausea, vomiting, drowsiness and headaches may be the more subtle signs of a brain tumour as many people put these symptoms down to tiredness, working too hard, or other illnesses,” he adds.

“But anyone who is experiencing headaches which are out of the ordinary for them should speak to their GP as soon as possible.”

Watch: Woman loses all her childhood memories after life saving surgery to remove brain tumour

Brain tumour treatments

As mentioned above, not all brain tumours are cancerous and some are less complicated than others, depending on where the tumour is located, among other things.

“Non-cancerous tumours can often be removed successfully with surgery and they very rarely grow back,” Dr Cichi explains.

“In some cases, a person may be able to live with their benign tumour for quite some time before they have surgery because they are slow-growing compared to cancerous tumours which grow at a much faster rate.”

Cancerous brain tumours can also be treated with surgery, as well as radiotherapy and chemotherapy if not all of the tumour could be removed in surgery.

“Different types of speech and physical therapy may be given if the tumour has affected motor skills, vision, and speech,” Dr Cichi adds.

What causes brain tumours?

Often, the cause of a brain tumour is unknown, but according to Dr Cichi they're more likely to develop in old age.

While most happen in 85 to 89-year-olds, they can affect people of any age, including children.

“Genetics (family history) can also play a part, and we know that exposure to radiation can increase the risk of developing some types of brain tumours,” he adds.

While this only accounts for a small number of brain tumours, some types are more common in those who have had radiotherapy, CT scans, or X-rays of the head.

What is glioblastoma?

Glioblastoma multiforme (GBM), the type of brain tumour Parker had (and Lola on EastEnders), is the most common type of brain tumour that starts in the brain.

According to The Brain Tumour Charity, it is the most aggressive form of adult brain tumour and is often resistant to treatment.

It is believed that the variety of cells in a glioblastoma is one of the reasons it is so hard to treat, because current drugs are not able to effectively target all the cell types in the tumour.

As with most brain tumours, the cause of glioblastoma is not known.

Read more: Tom Parker used cannabis as pain relief, The Wanted star's posthumous autobiography reveals

Brain Tumour Research says the first option for the treatment of GBM, if the tumour is operable, is surgery, usually followed by radiotherapy and chemotherapy.

“The surgical operation to remove a GBM is a delicate balancing act between removing as much of the tumour as possible and protecting the function of the healthy brain,” says a spokesperson for Brain Tumour Research.

“So the location of the brain tumour is very important with regard to both the potential impact of surgery and the symptoms that the patient will experience (because different areas of the brain control different mental and physical processes).”

How much of a glioblastoma a neurosurgeon can remove is limited because GBMs are 'diffuse', meaning that tumour cells invade healthy areas of the brain adjacent to the tumour.

Unfortunately, the nature of GBM means some tumour cells will almost always be left behind and hence will continue to grow.

For this reason, radiotherapy and chemotherapy are the next stages of treatment for a GBM. Usually, people are offered the chemotherapy drug Temozolomide (TMZ) alongside radiotherapy, and then further doses of Temozolomide afterwards.

For more information visit the NHS's website page on brain tumours.

You or your loved one being diagnosed with brain tumour can be frightening. But as well as your doctors and medical professionals being there to guide you through it, further support is out there too – visit The Brain Tumour Charity's website or call its helpline on 0808 800 0004.