Locations
Office
Sioux City, IA
Phone
Practice website
Insurances accepted
Aetna Life Insurance Company
UnitedHealthcare
Cigna
Golden Rule Insurance Company
About
Bio
Dr. Nielsen practices phlebology in Sioux City, Iowa. He is a diplomate of the American Board of Phlebology and is also board certified in general surgery by the American Board of Surgery and in cardiothoracic surgery by the American Board of Thoracic Surgery. He is a Fellow of the American College of Surgeons and the American College of Phlebology and is a member of the the Society of Thoracic Surgeons. He is a Registered Vascular Technologist by the American Registry for Diagnostic Medical Sonography (ARDMS). Dr. Nielsen practiced general surgery for three years and cardiothoracic and vascular surgery for seventeen years prior to dedicating his practice to the treatment of venous disease.
SpecialtiesDoctors may have more than one area of specialty interest. Board certification in a specialty area means the doctor has completed formal training and has practice experience in that specialty, and has passed the certification examination from the corresponding accredited medical specialty board.
Doctors may have more than one area of specialty interest. Board certification in a specialty area means the doctor has completed formal training and has practice experience in that specialty, and has passed the certification examination from the corresponding accredited medical specialty board.
Phlebology
Doctor Q&A
43 Answers
23 Agrees
The number of answers this doctor has agreed with.
A 22-year-old female asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
See your doc: If you have concerns about a blood clot of your leg, you should see your physician. Blood clots of the legs can cause pain and swelling, and discolora... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 41-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Phlebectomy?: If by "vein remova"l you are referring to surgical removal or micro-phlebectomy, you will likely see 2mm tiny incsions, often without incisions, and s... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 46-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
See vein specialist: I would recommend you see a vein specialist/phlebologist. He/she can evaluate your situation and give you recommendations as to how to treat your var... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 30-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Conservative Rx: Treatment of existing varicose veins, which often become larger and more symptomatic during pregnancy, revolves around treatment of symptoms and conse... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 29-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Gravity IS involved!: You are right! gravity alone will not cause varicose veins unless you also have vein insufficiency or improperly functioning valves of your veins whic... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 35-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Yep!: While treatment of both varicose veins and spider veins is quite effective in general, patient's should note that it is very possible that they might ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 44-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
See vein specialist: A vein specialist would examine your legs to see if you have significant vein issues to warrant an ultrasound of your legs veins. Depending on locati... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 34-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
There's help!: Spider veins are often due to hormonal changes a woman has as well as a heredity component. Treatment for spider veins can include sclerotherapy (inje... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 42-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
See your doctor: Thigh pain with walking may be due to various problems including hip arthritis, blockage of arteries to the legs, vein insufficiency, or various muscl... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 41-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Bulging veins: Varicose veins are bulging wormy-appearing veins, generally of the legs. They will typically get larger when you stand and then shrink up when you el... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 35-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Most likely: If the cause of your ulcer is venous in nature, compression stockings generally would be of benefit for patients with ulceration, blood clots, and var... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 40-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Treatment options: There are many treatment options for treating varicose veins. While these treatments are very beneficial in treating the varicose veins you have, it... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 30-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Leg varicose veins?: Treatment of typical leg varicose veins includes several possible modalities, including ablation or closure of veins with insufficient valves using la... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 36-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Yes: Both varicose and spider veins can be treated with sclerotherapy while evlt is used to treat (close) the vein that is causing the varicose veins to fo... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 34-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Not usually: Varicose veins may be asymptomatic or symptomatic. While varicose veins/venous insufficiency can sometimes result in superficial thrombophlebitis (bl... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 42-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Treat varicose veins: Prevention of recurrent superficial thrombophlebitis of varicose veins centers around the treatment of the varicose veins themselves. There are a var... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 39-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Yes: Dvt can affect any age although it is more common as one gets older. Young patients can develop DVT in situations where they are immobilized, bedridde... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 36-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Yes : Sclerotherapy is effective for the treatment of small spider veins, as long as they are of adequate size to successfully inject them. However, it is i... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 44-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
See your doctor: I would recommend making a visit to your doctor. Thigh pain of fairly recent duration could be due to injury but i would always be concerned about po... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 45-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Soon!: Recommendations as to when you can resume exercise vary from physician to physician. Generally, however, one can resume exercise immediately after sc... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 38-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
See vein specialist: I would see a vein specialist fopr evaluation of your varicose veins. However, you might get some relief by elevating your leg(s) intermittently, get... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 30-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Tiny needle!: Spider veins are injected with a very tiny needle. The chemical injected will remove the inner wall of the vein and cause it to close. Your body will... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 42-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Right away: After sclerotherapy, you are generally asked to do a lot of walking immediately after a treatment session and following. So, there's no need to chang... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 39-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Foam sclerotherapy: Varicose veins have been treated by sclerotherapy for years. Sclerotherapy involves injecting the varicosites with a chemical that basically removes t... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 30-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Shouldn't need any..: Sclerotherapy of varicose and spider veins involves using very small needles to inject the veins and is generally very well-tolerated and just slightl... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 39-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Nope....sorry : While compression hose may give one relief of venous insufficiency, including varicose veins and spider veins, they won't cure them. Spider veins can... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 34-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
See vein specialist: I would recommended seeing a vein specialist will likely recommend an ultrasound of you leg veins to look for the cause of your varicose veins. Often,... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 34-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Possible...: When varicose veins are treated with sclerotherapy, it is possible, but not common, that blood flow may be redistributed from the now closed varicosit... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 41-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Compression not cure: While compression stockings may reduce the discomfort associated with spider veins, it will not get rid of them. Sclerotherapy is quite successful in... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 45-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Pretty much: Usually varicose veins can be easily diagnosed on physicial exam, being those wormy bulging veins, generally of the legs. Your physician can determine... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 37-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Yes!: Yes, both spider vein and varicose veins usually are noted in the legs although spider veins can be found in many locations.
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 33-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Sometimes: Patients can experience some discomfort after sclerotherapy which may be due to inflammation of the treated vein, also known as phlebitis. Generally,... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 41-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
DVT vs PE: Thrombosis refers to the development of clot in an artery or vein while an embolus refers to the actual movement of that clot elsewhere. A typical ex... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 37-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Compression stocking: If you are willing to wear them, compression stockings will compress the bulging varicose veins and often provide quite a bit of relief from aching an... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 43-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Yes there's hope!: I would see a phlebologist (vein specialist) who will examine your legs and likely perform an ultrasound to determine the extent of your vein insuffic... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 35-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Discuss procedure: It depends on whether you have been worked up for your vein problems with a physical exam and ultrasound or whether you have already seen the doctor. ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 34-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
None to fade them...: There really are no home remedies for fading varicose veins away. You can, however, treat the symptoms (aching, heaviness, swelling) with compression ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 38-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Yes, kind of: Evlt, laser treatment, is generally used to treat the source or cause of the varicose veins....The vein with malfunctioning valves which leads to the ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 30-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Compression stocking: Venous insufficiency, and its typical aching pain, can be treated conservatively with compression stockings, exercise, and intermittent elevation of t... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 36-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Yep...sure can: Compression stockings can be very useful and actually the primary treatment in those patients with venous insufficiency, whether of the deep veins or ... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 46-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
Good results likely: I would recommend seeing a vein specialist/phlebologist who can speak with you, examine your legs, likely perform an ultrasound of the veins of your l... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 36-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
See a vein specialis: Recurrent hemorrhage from varicose veins should be addressed. Bleeding from varicose veins is caused by high pressure within the varicose vein caused... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
A 37-year-old member asked:

Dr. Mark Nielsenanswered
Phlebology 40 years experience
A little: Sclerotherapy involves using tiny needles to inject varicose or spider vein and is generally very well-tolerated with minimal discomfort. Sometimes pa... Read More
Created for people with ongoing healthcare needs but benefits everyone.
5.7k viewsReviewed >2 years ago
TestimonialsRecommendations and Thank you notes are endorsements given from patients or other doctors.
Recommendations and Thank you notes are endorsements given from patients or other doctors.
4
Recommendations
142
Thank you notes
Dr. Ted King
Jul 12, 2012
An excellent phlebologist and a terrific doctor.
Jul 12, 2012
Obviously great knowledge and experience
HealthTap member
Mar 30, 2015
Dr. Nielsen is an amazing doctor! #nationaldoctorsday2015 #virtualflower1
HealthTap member
Thank you, your answer was very helpful! Very grearfulx
HealthTap member
Thank you, your answer was very helpful!
HealthTap member
Thank you, your answer was very helpful!
Education & Training
Medical/Graduate school
University of North Dakota School of Medicine and Health Sciences, ND
Graduated 1983MD
Awards
Fellow of the American College of Surgeons
Fellow of the American College of Phlebology
Member, Society of Thoracic Surgeons
Affiliations
Siouxland Vein Center
90,000 U.S. doctors in 147 specialties are here to answer your questions, provide medical advice, write prescriptions, and more.
Answer emailed
in 24 hours or less