Causes

• Acne, including blackheads, is caused by one or more factors including hormones, oil-based cosmetics, genetics, medications, humidity, environmental pollutants, physical irritation and/or stress.
  
  

Forms of Acne

• Blackheads are just one form of acne. Some acne conditions include pus-filled cysts. According to Controllingacne.com, blackheads can be black or yellow and can result in a plug protruding from the skin. The pimple or blackhead contains sebum and keratin. Sebum darkens and causes the blackness of the pimple as the sebum oxidizes.
  
  

Diet

• Diet does play a role in whether you will be susceptible to developing blackheads. If your diet is high in glycemic foods and refined sugars, you may be prone to acne breakouts. If you don't have enough Vitamin E and A in your system, you may battle acne. Eat more protein and lots of fresh fruit, take a multivitamin and you should help reduce your skin problems.
  
  

Oily-Skin

• Oily-skinned individuals tend to have more blackheads than people who have dry skin. If you can eliminate the grease and oil on your skin this should help prevent blackheads. Clogged pores can cause blackheads. When comedones are open at the skin's surface they are called blackheads, according to Mayoclinic.com. The plugs in the hair follicles are dark as opposed to being white, as with whiteheads, which are closed comedones.
  
  

Teenagers and Lifestyle Choices

• Teenagers tend to be oilier than older people so they must be vigilant about keeping their face oil-free and clean. If you are under a lot of stress, don't be surprised if your face breaks out. Drinking alcohol and smoking can aggravate blackheads, according to Controllingacne.com.
  
  

Other Causes, Including Diseases

• Skincare21.net reports that blackheads can be caused by dehydration, facial oils seeping into pores, as noted above and dead cells that clog up pores. Remember to exfoliate on a regular basis. If an individual has an extreme case of skin inflammation called hidradenitis suppurativa he will have blackheads and lesions, which can result in scarring, according to Riversideonline.com. This conditions occurs when the hair follicle openings and oil glands get clogged and may be associated with such diseases as Grave's disease, herpes or Crohn's disease.