Hair loss can be a stressful occurrence, especially for those who discover their once crowning glory is now considerably thinner. The good news is there are brands out there that can help you alleviate the issue, or at least disguise the worst of it, with godsends such as root touch up powder for a quick fix. It does help however, to have a basic understanding of what may be causing the issue. According to Lisa Caddy, trichologist consultant and Philip Kingsley brand ambassador, hair shedding is caused by an internal disruption. "This type of hair loss occurs 6-12 weeks after the event that caused it," Caddy says. "It can be acute ... usually caused by a one-off blip, like the flu, food poisoning or high fever and doesn't require any treatment. However, hair loss that continues or reoccurs should be investigated further." The most common causes of reoccurring hair loss include deficiencies in iron, ferritin, vitamin B12 and D deficiency, high stress levels, crash dieting and high mercury levels. Caddy points out that hair grows its best from a healthy scalp, so anything you do to improve its condition will benefit your hair. "Give your scalp similar TLC to the skin on your face," she says. "Your scalp is your hair's support system, so it's important to keep it clean and healthy. Cleanse (shampoo) frequently, using a daily toner and treat your scalp to a weekly intensive targeted mask." Using a weekly pre-shampoo conditioning treatment, such as Philip Kingsley Elasticizer, may also help keep strands strong. Ultimately, treating reduced hair volume is not a quick fix, which can be frustrating. "Unfortunately, as hair thinning occurs gradually and is a genetic and progressive condition there are very few long-term treatments available," says Caddy. "However, a holistic approach is the best way to target hair thinning long term." She suggests the following: Eat a healthy, balanced diet rich in proteins, complex carbohydrates and iron. Ferritin deficiency is one of the most common causes of hair not growing past a certain length around the temples and sides of your scalp, so consider a nutritional supplement. Stress can inadvertently raise androgen (male hormone) levels, which can exacerbate reduced hair volume. Stress can also impact nutrient absorption, the health of your scalp and your immune system - all of which can affect hair growth.